The incident took place at about 9.40am at the prison, in Crow Spinney Lane, Perry, with the officer, understood to be female, taken to hospital following the attack, police said. Officers have launched an inquiry into the incident, with a 27-year-old man under investigation. The prison is home to more than 1,000 male inmates. A spokesman for the Ministry of Justice, which oversees the prison, said: We do not tolerate any violence against our hardworking staff and will always push for the strongest punishment. The prison is supporting the officer involved and this incident has been referred to the police. It would be inappropriate to comment further.