I found out much later in life that it was actually an adoption of Anton Chekhov's short story 'The Bet'. As far as i can remember the rich guy was played by Harihar Sharma (search 'kun mandir ma janchhau yatri' song on youtube) and the the poor guy who agrees to stay locked up was played by Ravi Giri ( I think he played the infamous किच्चु दादा in an earlier telefilim. Both veteran actors of nepal.

I can't remember the name of the show, but i am sure it is some translation of 'the bet'. Please post a link to the video if someone manages to locate it on youtube.