A second man has been charged over the death of an inmate at Pentonville Prison in north London.
Robert Butler, 30, was charged with the murder of 21-year-old Jamal Mahmoud on Tuesday (8 November). The alleged victim was found stabbed to death inside HMP Pentonville on 18 October.
Butler has now been remanded in custody ahead of a court appearance, with the date to be confirmed.
Another man, Basana Kimbembi, 34, was charged with Mahmoud's murder on 21 October.
He has since been remanded to appear before the Old Bailey via video link on 23 January 2017.
A third man, aged 26, had also arrested on suspicion of murder, but has now been released from police custody with no further action and returned to prison.
Mahmoud, from Enfield, was imprisoned after being convicted in July of this year of hiding a Skorpion machine gun in a woman's garden in Enfield.
It later emerged he was the father of a 10-month child at the time of his death. The Met Police said enquiries into the death continue.