I'm tring to use the API to delete a node and all its children using productTreeNode.DeleteAllCultures()

The problem I'm getting is that this produces a contraint error

Error
[DataConnection.ExecuteQuery]: Query: DELETE FROM CMS_Document WHERE [DocumentID] = @ID: caused exception: The DELETE statement conflicted with the REFERENCE constraint "FK__CMS_Attac__Attac__09A971A2". The conflict occurred in database "WMEC", table "dbo.CMS_Attachment", column 'AttachmentDocumentID'.
The statement has been terminated.

Is this the correct method to use or do I have to manually recurse through the tree and delete all children one by one.

Thanks
Nick