Up to one in 11 staff in some prisons across England and Wales have faced at least one misconduct investigation for allegations including sexual harassment and assault, Guardian analysis of Ministry of Justice data shows. The data, obtained via freedom of information laws, has revealed that for the year 2019-20, one in 11, or 9%, of staff at the Mount, a category C men’s prison in Hertfordshire, faced at least one misconduct investigation, the highest proportion of all prisons across England and Wales. After the Mount, the prisons with the highest rates of misconduct investigations include Cardiff prison, at 8.3% of its staff, followed by Nottingham (7.8%) and Swinfen Hall (7.8%). Staff at the Mount prison faced a disproportionate level of misconduct investigations, almost three times the average rate (3.39%), and has previously faced problems in its governance. In 2017, an incident occurred at the Mount in which prison officers were said to have lost control of two wings within the prison, leading to specialist riot-trained officers being called in to take control of the incident. At this time, inmates’ relatives also said that staff shortages meant prisoners were locked in their cells over the weekend. The prison was also subject to an action plan by HM Prison & Probation Service in 2019 following a 2018 inspection, which found that the prison was undergoing “significant difficulties”, that “governance and arrangements for accountability were seriously lacking”, and that “only just over half of prisoners felt respected”. For the financial year 2019-20, MoJ figures show that 1,266 prison staff faced at least one misconduct investigation, and of them 464 staff were subject to at least one conduct and discipline that concluded that year. Seventy-eight were recommended for dismissal. Furthermore, figures from the MoJ show that for all prison staff, a total of 13,432 misconduct investigations were brought between the financial years 2014-15 and 2019-20. Over the same period, 1,121 prison staff were dismissed for misconduct. Prison staff include anyone working in HM Prison Service or the Youth Custody Service. Andrew Neilson, the director of campaigns at the Howard League for Penal Reform, said: “It should come as no surprise that misconduct is an issue in an overcrowded prison system where people are warehoused in cells and staff are poorly paid and supported, without a clear purpose. “The solution to this problem begins with sensible steps to reduce the prison population.” In 2019, the Ministry of Justice launched a counter-corruption unit (CCU), as the department aims to tackle prisons becoming overcome with drugs, violence, and poor mental health among inmates. A prison service spokesperson from the Ministry of Justice said: “While the vast majority of prison staff are hardworking, dedicated and honest, these figures show that we take strong action against the small minority who break the rules.”