Index: lams_tool_sbmt/src/java/org/lamsfoundation/lams/tool/sbmt/service/SubmitFilesService.java
===================================================================
diff -u -r3eb8dcbf308a6b082c30d57f51e7000ebbe1c184 -r2e476d9e28e7598c2caf7c366dca0b995a9d50f3
--- lams_tool_sbmt/src/java/org/lamsfoundation/lams/tool/sbmt/service/SubmitFilesService.java	(.../SubmitFilesService.java)	(revision 3eb8dcbf308a6b082c30d57f51e7000ebbe1c184)
+++ lams_tool_sbmt/src/java/org/lamsfoundation/lams/tool/sbmt/service/SubmitFilesService.java	(.../SubmitFilesService.java)	(revision 2e476d9e28e7598c2caf7c366dca0b995a9d50f3)
@@ -244,6 +244,11 @@
 
 		toolService.removeActivityMark(user.getUserID(), session.getSessionID());
 
+		if (session.getGroupLeader() != null && session.getGroupLeader().getUid() == user.getUid()) {
+		    session.setGroupLeader(null);
+		    submitFilesSessionDAO.update(session);
+		}
+
 		submitUserDAO.delete(user);
 	    }
 	}