Madhur Bhandarkar and Neil Nitin Mukesh have been spotted visiting Thane jail recently but the pair have not been in trouble they are simply researching a film.
Madhur, who is known for his realistic films, will direct the film called Jail and Neil will play the lead.
A source said: "Madhur took his lead actor Neil Nitin Mukesh, to a Thane jail recently so that the two can observe for themselves what a jail actually looks like and how everyone there behaves.
"The two didn't get to interact with the prisoners as there were some rules to be followed.
Good to see they're are really putting their all into this film.