diff --git a/core/src/main/java/uk/gov/gchq/magmacore/service/MagmaCoreService.java b/core/src/main/java/uk/gov/gchq/magmacore/service/MagmaCoreService.java
index 80fa222a..a7418aac 100644
--- a/core/src/main/java/uk/gov/gchq/magmacore/service/MagmaCoreService.java
+++ b/core/src/main/java/uk/gov/gchq/magmacore/service/MagmaCoreService.java
@@ -345,6 +345,40 @@ public List<? extends Thing> findByPartialSignAndClassCaseSensitive(final String
 
     }
 
+    /**
+     * A case-sensitive search for entities in a specified class with a sign containing the given text
+     * that are referenced by an activity.
+     *
+     * @param wholeIri    The object that the required entities are composed into.
+     * @param text        The String to search for.
+     * @param classIri    The IRI of the class that the entities should be a member_of.
+     * @param pointInTime When the entities should have the matching sign.
+     * @return A {@link List} of {@link Thing}.
+     */
+    public List<? extends Thing> findByPartialSignByActivityReferenceAndClassCaseSensitive(final IRI wholeIri,
+            final String text, final IRI classIri,
+            final PointInTime pointInTime) {
+
+        final Set<Object> pointInTimeValues = pointInTime.value(HQDM.ENTITY_NAME);
+        if (pointInTimeValues == null || pointInTimeValues.isEmpty()) {
+            return List.of();
+        }
+
+        final Instant when = Instant.parse(pointInTimeValues.iterator().next().toString());
+
+        final QueryResultList queryResultList = database.executeQuery(String.format(
+                MagmaCoreServiceQueries.FIND_MEMBERS_OF_CLASS_BY_ACTIVITY_AND_PARTIAL_SIGN_CASE_SENSITIVE,
+                text, classIri, wholeIri,
+                text, classIri, wholeIri,
+                text, classIri, wholeIri));
+
+        // Filter by the pointInTime
+        final QueryResultList queryResults = filterByPointInTime(when, queryResultList);
+
+        return database.toTopObjects(queryResults);
+
+    }
+
     /**
      * A case-sensitive search for entities in a specified class with a sign containing the given text
      * that are parts of a given whole.
diff --git a/core/src/main/java/uk/gov/gchq/magmacore/service/sparql/MagmaCoreServiceQueries.java b/core/src/main/java/uk/gov/gchq/magmacore/service/sparql/MagmaCoreServiceQueries.java
index 8088e1b1..b84d34d4 100644
--- a/core/src/main/java/uk/gov/gchq/magmacore/service/sparql/MagmaCoreServiceQueries.java
+++ b/core/src/main/java/uk/gov/gchq/magmacore/service/sparql/MagmaCoreServiceQueries.java
@@ -544,6 +544,105 @@ public class MagmaCoreServiceQueries {
             order by ?s ?p ?o
             """;
 
+    /**
+     * A partial search by sign for entities referenced by an Activity.
+     */
+    public static final String FIND_MEMBERS_OF_CLASS_BY_ACTIVITY_AND_PARTIAL_SIGN_CASE_SENSITIVE = """
+            PREFIX hqdm: <http://www.semanticweb.org/hqdm#>
+            PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
+
+            SELECT distinct ?s ?p ?o ?start ?finish
+            WHERE {
+            {
+                SELECT ?s ?p ?o ?start ?finish
+                WHERE {
+                    BIND("%s" as ?text)
+                    BIND(<%s> as ?class)
+                    BIND(<%s> as ?topicId)
+
+                    ?sign hqdm:value_ ?signvalue;
+                        hqdm:member_of_ ?pattern.
+                    FILTER(CONTAINS(str(?signvalue), ?text))
+                    ?sos hqdm:temporal_part_of ?sign;
+                        hqdm:participant_in ?repBySign.
+                    ?rlc hqdm:participant_in ?repBySign.
+                    ?repBySign hqdm:represents ?state.
+                    ?state hqdm:temporal_part_of ?s.
+                    ?s hqdm:member_of ?class.
+                    ?topicId hqdm:references ?s.
+                    ?s ?p ?o.
+                    OPTIONAL {
+                        ?repBySign hqdm:beginning ?begin.
+                        ?begin hqdm:data_EntityName ?start.
+                    }
+                    OPTIONAL {
+                        ?repBySign hqdm:ending ?end.
+                        ?end hqdm:data_EntityName ?finish.
+                    }
+                    }
+                }
+                UNION
+                {
+                SELECT ?s (hqdm:value_ as ?p) ?o ?start ?finish
+                WHERE {
+                    BIND("%s" as ?text)
+                    BIND(<%s> as ?class)
+                    BIND(<%s> as ?topicId)
+
+                    ?sign hqdm:value_ ?o;
+                        hqdm:member_of_ ?pattern.
+                    FILTER(CONTAINS(str(?o), ?text))
+                    ?sos hqdm:temporal_part_of ?sign;
+                        hqdm:participant_in ?repBySign.
+                    ?rlc hqdm:participant_in ?repBySign.
+                    ?repBySign hqdm:represents ?state.
+                    ?state hqdm:temporal_part_of ?s.
+                    ?s hqdm:member_of ?class.
+                    ?topicId hqdm:references ?s.
+                    OPTIONAL {
+                        ?repBySign hqdm:beginning ?begin.
+                        ?begin hqdm:data_EntityName ?start.
+                    }
+                    OPTIONAL {
+                        ?repBySign hqdm:ending ?end.
+                        ?end hqdm:data_EntityName ?finish.
+                    }
+                    }
+                }
+                UNION
+                {
+                SELECT ?s (hqdm:data_EntityName as ?p) ?o ?start ?finish
+                WHERE {
+                    BIND("%s" as ?text)
+                    BIND(<%s> as ?class)
+                    BIND(<%s> as ?topicId)
+
+                    ?sign hqdm:value_ ?signValue;
+                        hqdm:member_of_ ?pattern.
+                    FILTER(CONTAINS(str(?signValue), ?text))
+                    ?sos hqdm:temporal_part_of ?sign;
+                        hqdm:participant_in ?repBySign.
+                    ?rlc hqdm:participant_in ?repBySign.
+                    ?repBySign hqdm:represents ?state.
+                    ?state hqdm:temporal_part_of ?s.
+                    ?s hqdm:member_of ?class.
+                    ?topicId hqdm:references ?s.
+                    ?s hqdm:member_of_kind ?kind.
+                    ?kind hqdm:data_EntityName ?o.
+                    OPTIONAL {
+                        ?repBySign hqdm:beginning ?begin.
+                        ?begin hqdm:data_EntityName ?start.
+                    }
+                    OPTIONAL {
+                        ?repBySign hqdm:ending ?end.
+                        ?end hqdm:data_EntityName ?finish.
+                    }
+                    }
+                }
+            }
+            order by ?s ?p ?o
+            """;
+
     /**
      * A partial search by sign for entities composed into a whole entity.
      */