[vtkusers] How to find the ids of duplicate points in vtkMergePoints

[Kiran, P (CORP, GEITC)]

Hi all:

I have set of 3D points contained in vtkPolyData., in which some of them are
duplicated.
I want to find the id's of duplicated points.

I saw vtkMergePoints where, we can check whether point is duplicated or not.

If there are some duplicated points, is it possible to find the id's of
those points?

pl. send me some suggestions.

Thanks
Regards
Kiran