Two inmates have escaped from Pentonville prison, it has emerged.
No details of the incident have yet been confirmed by the Ministry of Justice.
HMP Pentonville in north London is a category B Victorian prison which opened in 1842 and holds more than 1,200 adult men.
The prison was last year singled out by former justice secretary Michael Gove as "the most dramatic example of failure" within the estate.
Inmate Jamal Mahmoud, 21, died after being stabbed at the jail in an attack on October 18, which left two others injured.
The killing of the young father prompted calls for an inquiry into the state of prisons in England and Wales, with his family accusing the jail of "neglecting him".
Cuts to staff and resources by the Government meant the "tragedy" was "no massive surprise", the Prison Governors Association (PGA) said.
The latest development emerged after a major disturbance at another prison, HMP Bedford, on Sunday.