Update:

District Administration Office (Lalitpur) told that they do not certify the copy of passport (Though they were the ones to issue it).
They were kind of surprised and told that they never had such case.

The next step would be to go to the Ministry of Foreign Affairs. I will update how it goes.

नेपालको कनुन दैबले जानुन्!

In the mean time, if anybody has any suggestions, please post.

Thanks,
TTT