Index: source/gameengine/Ketsji/KX_GameObject.cpp
===================================================================
--- source/gameengine/Ketsji/KX_GameObject.cpp	(revision 50563)
+++ source/gameengine/Ketsji/KX_GameObject.cpp	(working copy)
@@ -110,7 +110,9 @@
       m_pHitObject(NULL),
       m_pObstacleSimulation(NULL),
       m_actionManager(NULL),
-      m_isDeformable(false)
+      m_isDeformable(false),
+      m_pDupliGroupObject(NULL),
+      m_pInstanceObjects(NULL)
 #ifdef WITH_PYTHON
     , m_attr_dict(NULL)
 #endif
@@ -168,6 +170,16 @@
 		KX_GetActiveScene()->RemoveAnimatedObject(this);
 		delete m_actionManager;
 	}
+
+	if (m_pDupliGroupObject)
+	{
+		m_pDupliGroupObject->Release();
+	}
+
+	if (m_pInstanceObjects)
+	{
+		m_pInstanceObjects->Release();
+	}
 #ifdef WITH_PYTHON
 	if (m_attr_dict) {
 		PyDict_Clear(m_attr_dict); /* in case of circular refs or other weird cases */
@@ -229,6 +241,46 @@
 	return m_pPhysicsController1;
 }
 
+KX_GameObject* KX_GameObject::GetDupliGroupObject()
+{ 
+	return m_pDupliGroupObject;	
+}
+
+CListValue* KX_GameObject::GetInstanceObjects()
+{ 
+	return m_pInstanceObjects;
+}
+
+void KX_GameObject::AddInstanceObjects(KX_GameObject* obj)
+{
+	if(!m_pInstanceObjects)
+		m_pInstanceObjects = new CListValue();
+
+	obj->AddRef();
+  	m_pInstanceObjects->Add(obj);
+}
+
+void KX_GameObject::RemoveInstanceObject(KX_GameObject* obj)
+{
+	assert(m_pInstanceObjects);
+	m_pInstanceObjects->RemoveValue(obj);
+	obj->Release();
+}
+
+void KX_GameObject::RemoveDupliGroupObject()
+{
+	if(m_pDupliGroupObject) {
+		m_pDupliGroupObject->Release();
+		m_pDupliGroupObject = NULL;
+	}
+}
+
+void KX_GameObject::SetDupliGroupObject(KX_GameObject* obj)
+{
+	obj->AddRef();
+	m_pDupliGroupObject = obj;
+}
+
 KX_GameObject* KX_GameObject::GetParent()
 {
 	KX_GameObject* result = NULL;
@@ -1629,6 +1681,8 @@
 PyAttributeDef KX_GameObject::Attributes[] = {
 	KX_PYATTRIBUTE_RO_FUNCTION("name",		KX_GameObject, pyattr_get_name),
 	KX_PYATTRIBUTE_RO_FUNCTION("parent",	KX_GameObject, pyattr_get_parent),
+	KX_PYATTRIBUTE_RO_FUNCTION("members",	KX_GameObject, pyattr_get_instance_objects),
+	KX_PYATTRIBUTE_RO_FUNCTION("group",	KX_GameObject, pyattr_get_dupli_group_object),
 	KX_PYATTRIBUTE_RO_FUNCTION("life",		KX_GameObject, pyattr_get_life),
 	KX_PYATTRIBUTE_RW_FUNCTION("mass",		KX_GameObject, pyattr_get_mass,		pyattr_set_mass),
 	KX_PYATTRIBUTE_RW_FUNCTION("linVelocityMin",		KX_GameObject, pyattr_get_lin_vel_min, pyattr_set_lin_vel_min),
@@ -1924,6 +1978,26 @@
 	Py_RETURN_NONE;
 }
 
+PyObject* KX_GameObject::pyattr_get_instance_objects(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	CListValue* instances = self->GetInstanceObjects();
+	if (instances) {
+		return instances->GetProxy();
+	}
+	Py_RETURN_NONE;
+}
+
+PyObject* KX_GameObject::pyattr_get_dupli_group_object(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	KX_GameObject* pivot = self->GetDupliGroupObject();
+	if (pivot) {
+		return pivot->GetProxy();
+	}
+	Py_RETURN_NONE;
+}
+
 PyObject* KX_GameObject::pyattr_get_life(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
 {
 	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
Index: source/gameengine/Ketsji/KX_GameObject.h
===================================================================
--- source/gameengine/Ketsji/KX_GameObject.h	(revision 50563)
+++ source/gameengine/Ketsji/KX_GameObject.h	(working copy)
@@ -116,6 +116,8 @@
 
 	KX_ObstacleSimulation*				m_pObstacleSimulation;
 
+	CListValue*						m_pInstanceObjects;
+	KX_GameObject*						m_pDupliGroupObject;
 
 	// The action manager is used to play/stop/update actions
 	BL_ActionManager*				m_actionManager;
@@ -208,6 +210,33 @@
 	void RemoveParent(KX_Scene *scene);
 
 	/*********************************
+	 * group reference API
+	 *********************************/
+
+		KX_GameObject*
+	GetDupliGroupObject(
+	);
+
+		CListValue*
+	GetInstanceObjects(
+	);
+
+		void	
+	SetDupliGroupObject(KX_GameObject*
+	);
+
+		void				
+	AddInstanceObjects(KX_GameObject*
+	);
+		
+		void 
+	RemoveDupliGroupObject(
+	);
+
+		void
+	RemoveInstanceObject(KX_GameObject*
+	);
+	/*********************************
 	 * Animation API
 	 *********************************/
 
@@ -949,6 +978,9 @@
 	static PyObject*	pyattr_get_name(void* self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 	static PyObject*	pyattr_get_parent(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 
+	static PyObject*	pyattr_get_dupli_group_object(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
+	static PyObject*	pyattr_get_instance_objects(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
+
 	static PyObject*	pyattr_get_life(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 	static PyObject*	pyattr_get_mass(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 	static int			pyattr_set_mass(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value);
Index: source/gameengine/Ketsji/KX_Scene.cpp
===================================================================
--- source/gameengine/Ketsji/KX_Scene.cpp	(revision 50564)
+++ source/gameengine/Ketsji/KX_Scene.cpp	(working copy)
@@ -769,6 +769,13 @@
 		// we can now add the graphic controller to the physic engine
 		replica->ActivateGraphicController(true);
 
+		// set references for dupli-group
+		// groupobj holds a list of all objects, that belongs to this group
+		groupobj->AddInstanceObjects(replica);
+
+		// every object gets the reference to its dupli-group object
+		replica->SetDupliGroupObject(groupobj);
+
 		// done with replica
 		replica->Release();
 	}
@@ -1017,6 +1024,20 @@
 			m_timemgr->RemoveTimeProperty(propval);
 		}
 	}
+
+	// if the object is the dupligroup proxy, you have to cleanup all m_pDupliGroupObject's in all
+	// instances refering to this group
+	if(newobj->GetInstanceObjects()) {
+		for (int i = 0; i < newobj->GetInstanceObjects()->GetCount(); i++) {
+			KX_GameObject* instance = (KX_GameObject*)newobj->GetInstanceObjects()->GetValue(i);
+			instance->RemoveDupliGroupObject();
+		}
+	}
+
+	// if this object was part of a group, make sure to remove it from that group's instance list
+	KX_GameObject* group = newobj->GetDupliGroupObject();
+	if (group)
+		group->RemoveInstanceObject(newobj);
 	
 	newobj->RemoveMeshes();
 	ret = 1;