diff --git a/backend/canisters/community/impl/src/updates/report_message.rs b/backend/canisters/community/impl/src/updates/report_message.rs
index f8df099c9d..85c6329489 100644
--- a/backend/canisters/community/impl/src/updates/report_message.rs
+++ b/backend/canisters/community/impl/src/updates/report_message.rs
@@ -26,6 +26,7 @@ async fn report_message(args: Args) -> Response {
             match result {
                 c2c_report_message::Response::Success => Success,
                 c2c_report_message::Response::AlreadyReported => AlreadyReported,
+                c2c_report_message::Response::InternalError(error) => InternalError(error),
             }
         }
         Err(err) => InternalError(format!("{err:?}")),
diff --git a/backend/canisters/group/impl/src/updates/report_message.rs b/backend/canisters/group/impl/src/updates/report_message.rs
index 4e3c261c31..86f0f3b594 100644
--- a/backend/canisters/group/impl/src/updates/report_message.rs
+++ b/backend/canisters/group/impl/src/updates/report_message.rs
@@ -26,6 +26,7 @@ async fn report_message(args: Args) -> Response {
             match result {
                 c2c_report_message::Response::Success => Success,
                 c2c_report_message::Response::AlreadyReported => AlreadyReported,
+                c2c_report_message::Response::InternalError(error) => InternalError(error),
             }
         }
         Err(err) => InternalError(format!("{err:?}")),
diff --git a/backend/canisters/group_index/CHANGELOG.md b/backend/canisters/group_index/CHANGELOG.md
index 3556c945ad..809b17c578 100644
--- a/backend/canisters/group_index/CHANGELOG.md
+++ b/backend/canisters/group_index/CHANGELOG.md
@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 
 - Add `events_ttl_last_updated` to chat summaries ([#4711](https://github.com/open-chat-labs/open-chat/pull/4711))
+- Implement `group_index::c2c_report_message` ([#4723](https://github.com/open-chat-labs/open-chat/pull/4723))
 
 ## [[2.0.926](https://github.com/open-chat-labs/open-chat/releases/tag/v2.0.926-group_index)] - 2023-11-03
 
diff --git a/backend/canisters/group_index/api/src/updates/c2c_report_message.rs b/backend/canisters/group_index/api/src/updates/c2c_report_message.rs
index a3420293a5..141937eb1a 100644
--- a/backend/canisters/group_index/api/src/updates/c2c_report_message.rs
+++ b/backend/canisters/group_index/api/src/updates/c2c_report_message.rs
@@ -17,4 +17,5 @@ pub struct Args {
 pub enum Response {
     Success,
     AlreadyReported,
+    InternalError(String),
 }
diff --git a/backend/canisters/group_index/impl/src/guards.rs b/backend/canisters/group_index/impl/src/guards.rs
index 77472b9e79..c454b8bc5a 100644
--- a/backend/canisters/group_index/impl/src/guards.rs
+++ b/backend/canisters/group_index/impl/src/guards.rs
@@ -23,3 +23,11 @@ pub fn caller_is_community_canister() -> Result<(), String> {
         Err("Caller is not a community canister".to_string())
     }
 }
+
+pub fn caller_is_group_or_community_canister() -> Result<(), String> {
+    if read_state(|state| state.is_caller_group_canister() || state.is_caller_community_canister()) {
+        Ok(())
+    } else {
+        Err("Caller is not a group or community canister".to_string())
+    }
+}
diff --git a/backend/canisters/group_index/impl/src/updates/c2c_report_message.rs b/backend/canisters/group_index/impl/src/updates/c2c_report_message.rs
new file mode 100644
index 0000000000..e0b759a42e
--- /dev/null
+++ b/backend/canisters/group_index/impl/src/updates/c2c_report_message.rs
@@ -0,0 +1,27 @@
+use crate::guards::caller_is_group_or_community_canister;
+use crate::read_state;
+use canister_api_macros::update_msgpack;
+use canister_tracing_macros::trace;
+use group_index_canister::c2c_report_message::{Response::*, *};
+
+#[update_msgpack(guard = "caller_is_group_or_community_canister")]
+#[trace]
+async fn c2c_report_message(args: Args) -> Response {
+    let user_index_canister_id = read_state(|state| state.data.user_index_canister_id);
+
+    let c2c_args = user_index_canister::c2c_report_message::Args {
+        chat_id: args.chat_id.into(),
+        reporter: args.reporter,
+        thread_root_message_index: args.thread_root_message_index,
+        message: args.message,
+        reason_code: args.reason_code,
+        notes: args.notes,
+        already_deleted: args.already_deleted,
+    };
+
+    match user_index_canister_c2c_client::c2c_report_message(user_index_canister_id, &c2c_args).await {
+        Ok(user_index_canister::c2c_report_message::Response::Success) => Success,
+        Ok(user_index_canister::c2c_report_message::Response::AlreadyReported) => AlreadyReported,
+        Err(error) => InternalError(format!("{error:?}")),
+    }
+}
diff --git a/backend/canisters/group_index/impl/src/updates/mod.rs b/backend/canisters/group_index/impl/src/updates/mod.rs
index 062ff36a59..b62a0549cc 100644
--- a/backend/canisters/group_index/impl/src/updates/mod.rs
+++ b/backend/canisters/group_index/impl/src/updates/mod.rs
@@ -10,6 +10,7 @@ pub mod c2c_make_private;
 pub mod c2c_mark_active;
 pub mod c2c_mark_community_active;
 pub mod c2c_mark_group_import_complete;
+pub mod c2c_report_message;
 pub mod c2c_start_importing_group_into_community;
 pub mod c2c_update_community;
 pub mod c2c_update_group;