diff --git a/testing/regress/ecl/dfucopy.ecl b/testing/regress/ecl/dfucopy.ecl
new file mode 100644
index 00000000000..bc3b6a53a6e
--- /dev/null
+++ b/testing/regress/ecl/dfucopy.ecl
@@ -0,0 +1,87 @@
+/*##############################################################################
+
+    HPCC SYSTEMS software Copyright (C) 2024 HPCC Systems®.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+############################################################################## */
+
+//noroxie
+//nohthor
+
+import Std.System;
+import Std.File AS FileServices;
+import $.setup;
+prefix := setup.Files(false, false).QueryFilePrefix;
+
+// Generate Data
+layout_user := RECORD
+   STRING20 user;
+END;
+
+layout_names := RECORD
+   STRING30 name;
+END;
+
+users1 := DATASET([{'Ned'},{'Robert'}, {'Jaime'}, {'Catelyn'}, {'Cersei'}, {'Daenerys'}, {'Jon'}], layout_user );
+users2 := DATASET([{'Sansa'}, {'Arya'}, {'Robb'}, {'Theon'}, {'Bran'}, {'Joffrey'}, {'Hound'}, {'Tyrion'}], layout_user );
+users3 := DATASET([{'Arya'}, {'Robb'}, {'Theon'}, {'Bran'}, {'Joffrey'}, {'Hound'}, {'Tyrion'}], layout_user );
+                   
+names := DATASET([{'Jack'},{'Oliver'},{'James'},{'Charlie'},{'Harris'},{'Lewis'},{'Leo'},{'Noah'},{'Alfie'},{'Rory'},{'Alexander'},{'Max'},{'Logan'},
+                  {'Lucas'},{'Harry'},{'Theo'},{'Thomas'},{'Brodie'},{'Archie'},{'Jacob'},{'Finlay'},{'Finn'},{'Daniel'},{'Joshua'},{'Oscar'},{'Arthur'},
+                  {'Hunter'},{'Ethan'},{'Mason'},{'Olivia'},{'Emily'},{'Isla'},{'Sophie'},{'Ella'},{'Ava'},{'Amelia'},{'Grace'},{'Freya'},{'Charlotte'},
+                  {'Jessica'},{'Lucy'},{'Ellie'},{'Sophia'},{'Aria'},{'Lily'},{'Harper'},{'Mia'},{'Rosie'},{'Millie'},{'Evie'},{'Eilidh'},{'Ruby'},
+                  {'Willow'},{'Anna'},{'Maisie'},{'Hannah'},{'Eva'},{'Chloe'}], layout_names);
+layout_rec := RECORD
+  STRING20 User;
+  STRING20 FirstName;
+  INTEGER id; 
+END;
+
+layout_rec f(layout_user l, layout_names r, INTEGER c) := TRANSFORM
+  SELF.user := TRIM(l.user,right)  + (c % 10000);
+  SELF.FirstName := r.name;
+  SELF.id := c;
+END;
+
+v1 := JOIN(users1, names, true, f(LEFT,RIGHT,COUNTER), ALL);
+v2 := JOIN(users2, names, true, f(LEFT,RIGHT,COUNTER), ALL);
+v3 := JOIN(users3, names, true, f(LEFT,RIGHT,COUNTER), ALL);
+
+layout_rec addCount(layout_rec l, INTEGER c) := TRANSFORM
+  SELF.id :=  c;
+  SELF := L;
+END;
+
+d1 := DISTRIBUTE(NORMALIZE(v1, 1000, addCount(LEFT, COUNTER)), HASH32(id));
+d2 := DISTRIBUTE(NORMALIZE(v2, 1000, addCount(LEFT, COUNTER)), HASH32(id));
+d3 := DISTRIBUTE(NORMALIZE(v3, 1000, addCount(LEFT, COUNTER)), HASH32(id));
+
+SEQUENTIAL(
+    OUTPUT(d1, , prefix + 'subdata1', OVERWRITE),
+    OUTPUT(d2, , prefix + 'subdata2', OVERWRITE),
+    OUTPUT(d3, , prefix + 'subdata3', OVERWRITE),
+    FileServices.CreateSuperFile(prefix + 'superdata'),
+    FileServices.StartSuperFileTransaction(),
+    FileServices.AddSuperFile(prefix + 'superdata',prefix + 'subdata1'),
+    FileServices.AddSuperFile(prefix + 'superdata',prefix + 'subdata2'),
+    FileServices.AddSuperFile(prefix + 'superdata',prefix + 'subdata3'),
+    FileServices.FinishSuperFileTransaction(),
+    FileServices.Copy(sourceLogicalName := prefix + 'superdata', destinationGroup:= 'mythor', destinationLogicalName := prefix + 'super_copy', ALLOWOVERWRITE := true),
+    FileServices.DeleteLogicalFile(prefix+'super_copy', true),
+    FileServices.DeleteOwnedSubFiles(prefix + 'superdata'),
+    FileServices.DeleteLogicalFile(prefix+'subdata1', true),
+    FileServices.DeleteLogicalFile(prefix+'subdata2', true),
+    FileServices.DeleteLogicalFile(prefix+'subdata3', true),
+    FileServices.DeleteLogicalFile(prefix+'superdata', true),
+)
+
diff --git a/testing/regress/ecl/key/dfucopy.xml b/testing/regress/ecl/key/dfucopy.xml
new file mode 100644
index 00000000000..d4331984355
--- /dev/null
+++ b/testing/regress/ecl/key/dfucopy.xml
@@ -0,0 +1,6 @@
+<Dataset name='Result 1'>
+</Dataset>
+<Dataset name='Result 2'>
+</Dataset>
+<Dataset name='Result 3'>
+</Dataset>