A Yorkshire prison has been dubbed unsafe and one of the country's most seriously overcrowded jails in the country.
Inspectors found levels of violence of all kinds were far too high at HMP Leeds in Armley, where 91 per cent of cells were holding more inmates than they were designed for.
The category B prison held more than 1,100 male inmates at the time it was inspected.
There were four self-inflicted deaths at the prison since it was last inspected in 2015, while another occurred during the latest visit in October and November.
HM Inspectorate of Prisons also found that in a survey, almost two-thirds of prisoners said it was easy to get illicit drugs in the establishment.
Mr Clarke added that there were some "cautious grounds for optimism" and noted that, unlike other prisons, HMP Leeds had not "slipped dramatically backwards" in its performance.
HM Prison and Probation Service, which runs the jail, responded to the report by saying levels of violence, self harm and drug use are too high.
Among the measures brought in to combat the issues are work with police to create a special intelligence unit to target drug suppliers and the roll out of body-worn cameras to support staff in reducing violence.