POLICE have launched an investigation after a prisoner was seriously injured in an attack by another inmate at a high-security jail near York.

The assault happened on Thursday at Full Sutton prison, which houses some of the country’s most dangerous criminals including terrorists and murderers.

Prisoners’ newspaper Converse said it had been told by sources at the jail that the prisoner who was attacked had his throat slashed and was now in a critical condition. The assault reportedly led to Full Sutton being placed into full lockdown, although this has not been confirmed by prison authorities.

A Prison Service spokeswoman said: “A prisoner at HMP Full Sutton was seriously assaulted by another prisoner on April 25.

“The victim was taken to an outside hospital for treatment and the police are investigating. We will not tolerate violence against prisoners or staff and will always press for the most serious charges to be laid against perpetrators.”