diff --git a/question/bank/managecategories/category.php b/question/bank/managecategories/category.php
index 183fff8f942..ade905f02ec 100644
--- a/question/bank/managecategories/category.php
+++ b/question/bank/managecategories/category.php
@@ -107,7 +107,7 @@ if ($param->delete) {
 
     helper::question_remove_stale_questions_from_category($param->delete);
 
-    $questionstomove = $DB->count_records('question_bank_entries', ['questioncategoryid' => $param->delete]);
+    $questionstomove = count($qcobject->get_real_question_ids_in_category($param->delete));
 
     // Second pass, if we still have questions to move, setup the form.
     if ($questionstomove) {
diff --git a/question/bank/managecategories/classes/question_category_object.php b/question/bank/managecategories/classes/question_category_object.php
index 39e6d561cc5..b84dfcc288d 100644
--- a/question/bank/managecategories/classes/question_category_object.php
+++ b/question/bank/managecategories/classes/question_category_object.php
@@ -324,17 +324,8 @@ class question_category_object {
      * @throws \dml_exception
      */
     public function move_questions(int $oldcat, int $newcat): void {
-        global $DB;
-
-        $sql = "SELECT q.id, 1
-                  FROM {question} q
-                  JOIN {question_versions} qv ON qv.questionid = q.id
-                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                 WHERE qbe.questioncategoryid = ?
-                   AND (q.parent = 0 OR q.parent = q.id)";
-
-        $questionids = $DB->get_records_sql_menu($sql, [$oldcat]);
-        question_move_questions_to_category(array_keys($questionids), $newcat);
+        $questionids = $this->get_real_question_ids_in_category($oldcat);
+        question_move_questions_to_category($questionids, $newcat);
     }
 
     /**
@@ -484,13 +475,7 @@ class question_category_object {
         // If the category name has changed, rename any random questions in that category.
         if ($oldcat->name != $cat->name) {
             // Get the question ids for each question category.
-            $sql = "SELECT q.id
-                      FROM {question} q
-                      JOIN {question_versions} qv ON qv.questionid = q.id
-                      JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                     WHERE qbe.questioncategoryid = ?";
-
-            $questionids = $DB->get_records_sql($sql, [$cat->id]);
+            $questionids = $this->get_real_question_ids_in_category($cat->id);
 
             foreach ($questionids as $question) {
                 $where = "qtype = 'random' AND id = ? AND " . $DB->sql_compare_text('questiontext') . " = ?";
@@ -516,4 +501,27 @@ class question_category_object {
             redirect($this->pageurl);
         }
     }
+
+    /**
+     * Returns ids of the question in the given question category.
+     *
+     * This method only returns the real question. It does not include
+     * subquestions of question types like multianswer.
+     *
+     * @param int $categoryid id of the category.
+     * @return int[] array of question ids.
+     */
+    public function get_real_question_ids_in_category(int $categoryid): array {
+        global $DB;
+
+        $sql = "SELECT q.id
+                  FROM {question} q
+                  JOIN {question_versions} qv ON qv.questionid = q.id
+                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+                 WHERE qbe.questioncategoryid = :categoryid
+                   AND (q.parent = 0 OR q.parent = q.id)";
+
+        $questionids = $DB->get_records_sql($sql, ['categoryid' => $categoryid]);
+        return array_keys($questionids);
+    }
 }
diff --git a/question/bank/managecategories/tests/behat/question_categories.feature b/question/bank/managecategories/tests/behat/question_categories.feature
index e2b8e7c7bd5..9c32b807fdd 100644
--- a/question/bank/managecategories/tests/behat/question_categories.feature
+++ b/question/bank/managecategories/tests/behat/question_categories.feature
@@ -71,3 +71,20 @@ Feature: A teacher can put questions in categories in the question bank
     Then I should not see "Used category"
     And I follow "Add category"
     And I should see "Default for C1 (1)"
+
+  @_file_upload
+  Scenario: Multi answer questions with their child questions can be moved to another category when the current category is deleted
+    When I navigate to "Question bank" in current page administration
+    And I select "Import" from the "Question bank tertiary navigation" singleselect
+    And I set the field "id_format_xml" to "1"
+    And I upload "question/format/xml/tests/fixtures/multianswer.xml" file to "Import" filemanager
+    And I press "id_submitbutton"
+    And I press "Continue"
+    And I select "Categories" from the "Question bank tertiary navigation" singleselect
+    And I click on "Delete" "link" in the "Default for Test images in backup" "list_item"
+    And I should see "The category 'Default for Test images in backup' contains 1 questions"
+    And I select "Used category" from the "Category" singleselect
+    And I press "Save in category"
+    Then I should not see "Default for Test images in backup"
+    And I follow "Add category"
+    And I should see "Used category (2)"
diff --git a/question/bank/managecategories/tests/helper_test.php b/question/bank/managecategories/tests/helper_test.php
index f59865247f0..12c9cf113f7 100644
--- a/question/bank/managecategories/tests/helper_test.php
+++ b/question/bank/managecategories/tests/helper_test.php
@@ -16,6 +16,9 @@
 
 namespace qbank_managecategories;
 
+use moodle_url;
+use core_question\local\bank\question_edit_contexts;
+
 /**
  * Unit tests for helper class.
  *
@@ -47,6 +50,11 @@ class helper_test extends \advanced_testcase {
      */
     protected $quiz;
 
+    /**
+     * @var question_category_object used in the tests.
+     */
+    protected $qcobject;
+
     /**
      * Tests initial setup.
      */
@@ -60,6 +68,12 @@ class helper_test extends \advanced_testcase {
         $this->quiz = $datagenerator->create_module('quiz', ['course' => $this->course->id]);
         $this->qgenerator = $datagenerator->get_plugin_generator('core_question');
         $this->context = \context_module::instance($this->quiz->cmid);
+
+        $contexts = new question_edit_contexts($this->context);
+        $this->qcobject = new question_category_object(null,
+            new moodle_url('/question/bank/managecategories/category.php', ['courseid' => SITEID]),
+            $contexts->having_one_edit_tab_cap('categories'), 0, null, 0,
+            $contexts->having_cap('moodle/question:add'));
     }
 
     /**
@@ -98,45 +112,25 @@ class helper_test extends \advanced_testcase {
         $q1b = $this->qgenerator->create_question('random', null, ['category' => $qcat1->id]);          // Will not be used.
         $q2c = $this->qgenerator->create_question('random', null, ['category' => $qcat2->id]);          // Will not be used.
 
-        $sql = "SELECT count(q.id)
-                  FROM {question} q
-                  JOIN {question_versions} qv ON qv.questionid = q.id
-                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                 WHERE qbe.questioncategoryid = ?";
-        $this->assertEquals(2, $DB->count_records_sql($sql, [$qcat1->id]));
-        $this->assertEquals(3, $DB->count_records_sql($sql, [$qcat2->id]));
+        $this->assertEquals(2, count($this->qcobject->get_real_question_ids_in_category($qcat1->id)));
+        $this->assertEquals(3, count($this->qcobject->get_real_question_ids_in_category($qcat2->id)));
 
         // Non-existing category, nothing will happen.
         helper::question_remove_stale_questions_from_category(0);
-        $sql = "SELECT count(q.id)
-                  FROM {question} q
-                  JOIN {question_versions} qv ON qv.questionid = q.id
-                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                 WHERE qbe.questioncategoryid = ?";
-        $this->assertEquals(2, $DB->count_records_sql($sql, [$qcat1->id]));
-        $this->assertEquals(3, $DB->count_records_sql($sql, [$qcat2->id]));
+        $this->assertEquals(2, count($this->qcobject->get_real_question_ids_in_category($qcat1->id)));
+        $this->assertEquals(3, count($this->qcobject->get_real_question_ids_in_category($qcat2->id)));
 
         // First category, should be empty afterwards.
         helper::question_remove_stale_questions_from_category($qcat1->id);
-        $sql = "SELECT count(q.id)
-                  FROM {question} q
-                  JOIN {question_versions} qv ON qv.questionid = q.id
-                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                 WHERE qbe.questioncategoryid = ?";
-        $this->assertEquals(0, $DB->count_records_sql($sql, [$qcat1->id]));
-        $this->assertEquals(3, $DB->count_records_sql($sql, [$qcat2->id]));
+        $this->assertEquals(0, count($this->qcobject->get_real_question_ids_in_category($qcat1->id)));
+        $this->assertEquals(3, count($this->qcobject->get_real_question_ids_in_category($qcat2->id)));
         $this->assertFalse($DB->record_exists('question', ['id' => $q1a->id]));
         $this->assertFalse($DB->record_exists('question', ['id' => $q1b->id]));
 
         // Second category, used questions should be left untouched.
         helper::question_remove_stale_questions_from_category($qcat2->id);
-        $sql = "SELECT count(q.id)
-                  FROM {question} q
-                  JOIN {question_versions} qv ON qv.questionid = q.id
-                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
-                 WHERE qbe.questioncategoryid = ?";
-        $this->assertEquals(0, $DB->count_records_sql($sql, [$qcat1->id]));
-        $this->assertEquals(1, $DB->count_records_sql($sql, [$qcat2->id]));
+        $this->assertEquals(0, count($this->qcobject->get_real_question_ids_in_category($qcat1->id)));
+        $this->assertEquals(1, count($this->qcobject->get_real_question_ids_in_category($qcat2->id)));
         $this->assertFalse($DB->record_exists('question', ['id' => $q2a->id]));
         $this->assertTrue($DB->record_exists('question', ['id' => $q2b->id]));
         $this->assertFalse($DB->record_exists('question', ['id' => $q2c->id]));
diff --git a/question/bank/managecategories/tests/question_category_object_test.php b/question/bank/managecategories/tests/question_category_object_test.php
index ed889290982..8b6efbaacd7 100644
--- a/question/bank/managecategories/tests/question_category_object_test.php
+++ b/question/bank/managecategories/tests/question_category_object_test.php
@@ -340,4 +340,100 @@ class question_category_object_test extends \advanced_testcase {
         $this->assertDebuggingNotCalled();
 
     }
+
+    /**
+     * Test that get_real_question_ids_in_category() returns question id
+     * of a shortanswer question in a category.
+     *
+     * @covers ::get_real_question_ids_in_category
+     */
+    public function test_get_real_question_ids_in_category_shortanswer() {
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $categoryid = $this->defaultcategoryobj->id;
+
+        // Short answer question is made of one question.
+        $shortanswer = $generator->create_question('shortanswer', null, ['category' => $categoryid]);
+        $questionids = $this->qcobject->get_real_question_ids_in_category($categoryid);
+        $this->assertCount(1, $questionids);
+        $this->assertContains($shortanswer->id, $questionids);
+    }
+
+    /**
+     * Test that get_real_question_ids_in_category() returns question id
+     * of a multianswer question in a category.
+     *
+     * @covers ::get_real_question_ids_in_category
+     */
+    public function test_get_real_question_ids_in_category_multianswer() {
+        global $DB;
+        $countq = $DB->count_records('question');
+        $countqbe = $DB->count_records('question_bank_entries');
+
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $categoryid = $this->defaultcategoryobj->id;
+
+        // Multi answer question is made of one parent and two child questions.
+        $multianswer = $generator->create_question('multianswer', null, ['category' => $categoryid]);
+        $questionids = $this->qcobject->get_real_question_ids_in_category($categoryid);
+        $this->assertCount(1, $questionids);
+        $this->assertContains($multianswer->id, $questionids);
+        $this->assertEquals(3, $DB->count_records('question') - $countq);
+        $this->assertEquals(3, $DB->count_records('question_bank_entries') - $countqbe);
+    }
+
+    /**
+     * Test that get_real_question_ids_in_category() returns question ids
+     * of two versions of a multianswer question in a category.
+     *
+     * @covers ::get_real_question_ids_in_category
+     */
+    public function test_get_real_question_ids_in_category_multianswer_two_versions() {
+        global $DB;
+        $countq = $DB->count_records('question');
+        $countqv = $DB->count_records('question_versions');
+        $countqbe = $DB->count_records('question_bank_entries');
+
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $categoryid = $this->defaultcategoryobj->id;
+
+        // Create two versions of a multianswer question which will lead to
+        // 2 parents and 4 child questions in the question bank.
+        $multianswer = $generator->create_question('multianswer', null, ['category' => $categoryid]);
+        $multianswernew = $generator->update_question($multianswer, null, ['name' => 'This is a new version']);
+        $questionids = $this->qcobject->get_real_question_ids_in_category($categoryid);
+        $this->assertCount(2, $questionids);
+        $this->assertContains($multianswer->id, $questionids);
+        $this->assertContains($multianswernew->id, $questionids);
+        $this->assertEquals(6, $DB->count_records('question') - $countq);
+        $this->assertEquals(6, $DB->count_records('question_versions') - $countqv);
+        $this->assertEquals(3, $DB->count_records('question_bank_entries') - $countqbe);
+    }
+
+    /**
+     * Test that get_real_question_ids_in_category() returns question id
+     * of a multianswer question in a category even if their child questions are
+     * linked to a category that doesn't exist.
+     *
+     * @covers ::get_real_question_ids_in_category
+     */
+    public function test_get_real_question_ids_in_category_multianswer_bad_data() {
+        global $DB;
+        $countqbe = $DB->count_records('question_bank_entries');
+
+        $generator = $this->getDataGenerator()->get_plugin_generator('core_question');
+        $categoryid = $this->defaultcategoryobj->id;
+
+        // Multi answer question is made of one parent and two child questions.
+        $multianswer = $generator->create_question('multianswer', null, ['category' => $categoryid]);
+        $qversion = $DB->get_record('question_versions', ['questionid' => $multianswer->id]);
+
+        // Update category id for child questions to a category that doesn't exist.
+        $DB->set_field_select('question_bank_entries', 'questioncategoryid',
+            123456, 'id <> :id', ['id' => $qversion->questionbankentryid]);
+
+        $questionids = $this->qcobject->get_real_question_ids_in_category($categoryid);
+        $this->assertCount(1, $questionids);
+        $this->assertContains($multianswer->id, $questionids);
+        $this->assertEquals(3, $DB->count_records('question_bank_entries') - $countqbe);
+    }
 }