"Qateel was murdered in the jail," a senior ATS official told PTI.
Qateel was suspected to have been strangled to death by some inmates following a brawl, police said.
Qateel, who was also involved in Bangalore Chinnaswamy stadium blast, had been arrested by Maharashtra ATS for his attempt to carry out terror strike by planting a bomb outside Shrimant Dagdusheth Halwai Ganapti Temple. However, his bid was foiled.
He was arrested in November last year by the Delhi Police for his involvement in various blasts in the country.
The reason and motive for the killing is currently being investigated by the police.
