diff --git a/datagateway_api/src/search_api/models.py b/datagateway_api/src/search_api/models.py
index 2fc1e3ad..4b8eebc3 100644
--- a/datagateway_api/src/search_api/models.py
+++ b/datagateway_api/src/search_api/models.py
@@ -111,6 +111,19 @@ def from_icat(cls, icat_data, required_related_fields):  # noqa: B902, N805
                 # we have to get hold of its class definition and call its `from_icat`
                 # method to create an instance of itself with the ICAT data provided.
                 # Doing this allows for recursion.
+
+                if entity_field_alias not in [
+                    required_related_field.split(".")[0]
+                    for required_related_field in required_related_fields
+                ]:
+                    # Before proceeding, check if the related entity really needs to be created.
+                    # Do not attempt to create the related entity if ICAT data for it is available
+                    # but the entity has not been specified to be included. In such cases, the ICAT
+                    # data is likely available because the data for another entity field is
+                    # retrieved via that ICAT entity. We do not want to return data for related
+                    # entities unless explicitly specified to be included by the user.
+                    continue
+
                 data = (
                     [field_value] if not isinstance(field_value, list) else field_value
                 )
diff --git a/test/search_api/test_models.py b/test/search_api/test_models.py
index f88d0ec1..222e9c41 100644
--- a/test/search_api/test_models.py
+++ b/test/search_api/test_models.py
@@ -411,8 +411,6 @@ def test_from_icat_document_entity_with_data_for_all_related_entities(self):
         expected_entity_data["pid"] = f"pid:{INVESTIGATION_ICAT_DATA['id']}"
         expected_entity_data["doi"] = None
         expected_entity_data["datasets"] = [DATASET_PANOSC_DATA, DATASET_PANOSC_DATA]
-        expected_entity_data["members"] = [MEMBER_PANOSC_DATA]
-        expected_entity_data["parameters"] = [PARAMETER_PANOSC_DATA]
 
         icat_data = INVESTIGATION_ICAT_DATA.copy()
         icat_data["doi"] = None
@@ -434,7 +432,6 @@ def test_from_icat_file_entity_without_data_for_related_entities(self):
 
     def test_from_icat_file_entity_with_data_for_all_related_entities(self):
         expected_entity_data = FILE_PANOSC_DATA.copy()
-        expected_entity_data["dataset"] = DATASET_PANOSC_DATA
 
         icat_data = DATAFILE_ICAT_DATA.copy()
         icat_data["dataset"] = DATASET_ICAT_DATA