A murder investigation has been launched into the death of an inmate who was attacked at a high-security prison.
The 36-year-old prisoner was found with head injuries at HMP Belmarsh, south-east London, at 20:00 GMT on Tuesday, Scotland Yard said.
He was taken to hospital in a critical condition but died on Wednesday night.
Two 28-year-old inmates were arrested on Tuesday evening on suspicion of attempted murder.
Det Ch Insp Richard Leonard said: “At this stage I am open minded concerning motive, but expect this to become clear as the investigation progresses.”
The Met is working to establish the circumstances surrounding the death with prison operator Serco and local prison staff.
A post-mortem examination will take place in due course.
HMP Belmarsh is one of only three high-security core prisons in England and Wales.
A 2018 inspection report showed that levels of violence had increased at Belmarsh since a previous inspection in 2015.
The jail opened in 1991 and is able to hold 910 prisoners, according to the Ministry of Justice.