The Director of Prisons, Superintendent Sandro Gatt, has been replaced at his own request, the Ministry of Home Affairs said this afternoon.
It said Supt Gatt yesterday asked to be re-assigned to the police force and the request was accepted.
Inspector Abraham Zammit, currently deputy director of prisons, has taken over in an acting capacity.
The Ministry of Home Affairs has also appointed Mr Emanuel Cassar to head an independent board to investigate reports on alleged shortcomings at the prisons.
Supt Gatt has been in the eye of a storm after report that a prisoner was beaten up by prison guards and others, carried in The Sunday Times, that prisoner Leli Camilleri, known as Il-Bully, acted as an intermediary between the prisoners and the prison authorities. Supt Gatt had said that inmates were not forced to go through Mr Camilleri and he saw a number of prisoners every day.