diff --git a/lib/deprecatedlib.php b/lib/deprecatedlib.php
index 0c24640bab2..79775c89f73 100644
--- a/lib/deprecatedlib.php
+++ b/lib/deprecatedlib.php
@@ -5616,7 +5616,11 @@ function message_is_user_blocked($recipient, $sender = null) {
     debugging('message_is_user_blocked() is deprecated and is no longer used, please use
         \core_message\api::is_user_blocked() instead.', DEBUG_DEVELOPER);
 
-    return \core_message\api::is_user_blocked($recipient, $sender);
+    $senderid = null;
+    if ($sender !== null && isset($sender->id)) {
+        $senderid = $sender->id;
+    }
+    return \core_message\api::is_user_blocked($recipient->id, $senderid);
 }
 
 /**
diff --git a/message/classes/api.php b/message/classes/api.php
index eabe7d7379b..0d90dae5f71 100644
--- a/message/classes/api.php
+++ b/message/classes/api.php
@@ -601,8 +601,12 @@ class api {
             return false;
         }
 
+        $senderid = null;
+        if ($sender !== null && isset($sender->id)) {
+            $senderid = $sender->id;
+        }
         // The recipient has specifically blocked this sender.
-        if (self::is_user_blocked($recipient, $sender)) {
+        if (self::is_user_blocked($recipient->id, $senderid)) {
             return false;
         }
 
@@ -648,27 +652,25 @@ class api {
      * Note: This function will always return false if the sender has the
      * readallmessages capability at the system context level.
      *
-     * @param object $recipient User object.
-     * @param object $sender User object.
+     * @param int $recipientid User ID of the recipient.
+     * @param int $senderid User ID of the sender.
      * @return bool true if $sender is blocked, false otherwise.
      */
-    public static function is_user_blocked($recipient, $sender = null) {
+    public static function is_user_blocked($recipientid, $senderid = null) {
         global $USER, $DB;
 
-        if (is_null($sender)) {
+        if (is_null($senderid)) {
             // The message is from the logged in user, unless otherwise specified.
-            $sender = $USER;
+            $senderid = $USER->id;
         }
 
         $systemcontext = \context_system::instance();
-        if (has_capability('moodle/site:readallmessages', $systemcontext, $sender)) {
+        if (has_capability('moodle/site:readallmessages', $systemcontext, $senderid)) {
             return false;
         }
 
-        if ($contact = $DB->get_record('message_contacts', array('userid' => $recipient->id, 'contactid' => $sender->id))) {
-            if ($contact->blocked) {
-                return true;
-            }
+        if ($DB->get_field('message_contacts', 'blocked', ['userid' => $recipientid, 'contactid' => $senderid])) {
+            return true;
         }
 
         return false;
diff --git a/message/classes/output/messagearea/messages.php b/message/classes/output/messagearea/messages.php
index 368d1d08ec6..e967ec15dcd 100644
--- a/message/classes/output/messagearea/messages.php
+++ b/message/classes/output/messagearea/messages.php
@@ -26,6 +26,7 @@ namespace core_message\output\messagearea;
 
 defined('MOODLE_INTERNAL') || die();
 
+use core_message\api;
 use renderable;
 use templatable;
 
@@ -95,6 +96,8 @@ class messages implements templatable, renderable {
             $data->messages[] = $message->export_for_template($output);
         }
 
+        $data->isblocked = api::is_user_blocked($this->currentuserid, $this->otheruserid);
+
         return $data;
     }
 }
diff --git a/message/externallib.php b/message/externallib.php
index 2ecaf66b101..1d394bcac98 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -970,7 +970,8 @@ class core_message_external extends external_api {
                 'isonline' => new external_value(PARAM_BOOL, 'The user\'s online status'),
                 'messages' => new external_multiple_structure(
                     self::get_messagearea_message_structure()
-                )
+                ),
+                'isblocked' => new external_value(PARAM_BOOL, 'Is this user blocked by the current user?', VALUE_DEFAULT, false),
             )
         );
     }
diff --git a/message/templates/message_area_messages_area.mustache b/message/templates/message_area_messages_area.mustache
index acfa4494a37..ebafaec1c79 100644
--- a/message/templates/message_area_messages_area.mustache
+++ b/message/templates/message_area_messages_area.mustache
@@ -14,6 +14,37 @@
     You should have received a copy of the GNU General Public License
     along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 }}
+{{!
+    @template core_message/message_area_messages_area
+
+    Messages area template.
+
+    Classes required for JS:
+    * none
+
+    Data attributes required for JS:
+    * none
+
+    Context variables required for this template:
+    * isonline - boolean
+    * isblocked - boolean
+    * otheruserid - int
+    * otheruserfullname - string
+    * messages - array of messages
+
+    Example context (json):
+    {
+        "isonline": true,
+        "isblocked": true,
+        "otheruserid": 1,
+        "otheruserfullname": "Sam Student",
+        "messages": [
+            {
+                "text": "Hello there!"
+            }
+        ]
+    }
+}}
 {{#otheruserid}}
 <div class="messages-header">
     <div class="view-toggle btn-container">
@@ -25,6 +56,11 @@
     <div class="name-container">
         <div class="name">
             <button class="btn btn-link" data-action="view-contact-profile" data-userid="{{otheruserid}}">{{otheruserfullname}}</button>
+            {{#isblocked}}
+                <span data-region="contact-icon-blocked">
+                    {{#pix}} t/block, core, {{#str}} contactblocked, message {{/str}} {{/pix}}
+                </span>
+            {{/isblocked}}
         </div>
         <div class="status {{#isonline}}online{{/isonline}}">
             <span class="offline-text">{{#str}} offline, message {{/str}}</span>
diff --git a/message/tests/api_test.php b/message/tests/api_test.php
index 67d898ed569..803ae64b30c 100644
--- a/message/tests/api_test.php
+++ b/message/tests/api_test.php
@@ -839,13 +839,13 @@ class core_message_api_testcase extends core_message_messagelib_testcase {
         $this->setUser($user1);
 
         // User shouldn't be blocked.
-        $this->assertFalse(\core_message\api::is_user_blocked($user1, $user2));
+        $this->assertFalse(\core_message\api::is_user_blocked($user1->id, $user2->id));
 
         // Block the user.
         message_block_contact($user2->id);
 
         // User should be blocked.
-        $this->assertTrue(\core_message\api::is_user_blocked($user1, $user2));
+        $this->assertTrue(\core_message\api::is_user_blocked($user1->id, $user2->id));
     }
 
     /**
@@ -865,7 +865,7 @@ class core_message_api_testcase extends core_message_messagelib_testcase {
         $this->setAdminUser();
 
         // As the admin you should still be able to send messages to the user.
-        $this->assertFalse(\core_message\api::is_user_blocked($user1));
+        $this->assertFalse(\core_message\api::is_user_blocked($user1->id));
     }
 
     /*