A murder probe is underway after the death of a 33-year-old man at HMP Risley in Cheshire.
It is believed Stephen O’Donnell was stabbed during an incident on E wing in the Category C men’s prison.
A spokesman for Cheshire Police said: “At 7.41 on Tuesday 22 January police were called to reports of an assault at HMP in Warrington. A 33-year-old was taken to Warrington General Hospital where he sadly died.
“Formal identification has not yet taken place but his family have been informed and are being supported by specialist officers.
“A 23-year-old man has been arrested on suspicion of murder and is currently in police custody assisting detectives with their enquiries.”
A Prison Service spokesman said: “HMP Risley prisoner Stephen O’Donnell was pronounced dead following an incident on Tuesday evening.
“Our condolences are with the friends and family of Mr O’Donnell and it would be inappropriate to comment further while there is an ongoing police investigation.”