An undertrial allegedly committed suicide in Thane Central Jail, police said.
Siraj Alam Shaikh, 27, was found hanging in the jail premises late on Monday evening, they said.
Shaikh was arrested for alleged kidnapping and rape of a girl by Mumbai Police and lodged in prison since last year, Thane Nagar police said.
He was shifted to Thane Jail only a few days back from the Taloja Jail where he was lodged earlier, they said.
During the head count on Monday evening, the jail officials found one of the prisoners missing. During the search, they allegedly found Shaikh hanging in the cell.
He was brought down and taken to the jail medical ward where a doctor examined him. He was then rushed to Thane civil hospital where doctors declared him brought dead.
The body was sent for postmortem, police said, adding that a case has been registered.