diff --git a/src/app/features/reporting/query.service.spec.ts b/src/app/features/reporting/query.service.spec.ts
index e8c83b4911..4abdffee05 100644
--- a/src/app/features/reporting/query.service.spec.ts
+++ b/src/app/features/reporting/query.service.spec.ts
@@ -498,6 +498,22 @@ describe("QueryService", () => {
     expect(result).toEqual(["custom-string", "custom-string"]);
   });
 
+  it("should omit participants which can be found anymore (e.g. deleted participants)", async () => {
+    const maleChild = await createChild("M");
+    const femaleChild = await createChild("F");
+    await createNote(new Date(), [
+      { child: maleChild, status: presentAttendanceStatus },
+      { child: femaleChild, status: presentAttendanceStatus },
+    ]);
+    await entityMapper.remove(femaleChild);
+
+    const result = await service.queryData(
+      `${EventNote.ENTITY_TYPE}:toArray:getIds(children):toEntities(${Child.ENTITY_TYPE}).gender`
+    );
+
+    expect(result).toEqual([maleChild.gender]);
+  });
+
   async function createChild(
     gender: "M" | "F" = "F",
     religion?: "muslim" | "christian"
diff --git a/src/app/features/reporting/query.service.ts b/src/app/features/reporting/query.service.ts
index 8c16e46d24..e925a32e08 100644
--- a/src/app/features/reporting/query.service.ts
+++ b/src/app/features/reporting/query.service.ts
@@ -123,7 +123,7 @@ export class QueryService {
    * @returns a list where every string has the prefix
    */
   private addPrefix(ids: string[], prefix: string): string[] {
-    return ids.map((id) => (id.startsWith(prefix) ? id : prefix + ":" + id));
+    return ids.map((id) => Entity.createPrefixedId(prefix, id));
   }
 
   /**
@@ -171,10 +171,12 @@ export class QueryService {
       ids = this.addPrefix(ids, entityPrefix);
     }
 
-    return ids.map((id) => {
-      const prefix = id.split(":")[0];
-      return this.entities[prefix][id];
-    });
+    return ids
+      .map((id) => {
+        const prefix = id.split(":")[0];
+        return this.entities[prefix][id];
+      })
+      .filter((entity) => !!entity);
   }
 
   /**