A spate of transgender prisoner deaths underlines the need for action to address the issue, a watchdog has said.
Prisons and Probation Ombudsman Nigel Newcomen said jails should be more flexible and proactive in managing such inmates.
In the latest incident, Jenny Swift, an inmate at all-male HMP Doncaster, was found dead in her cell on December 30.
Newcomen said his office has historically received few complaints from prisoners identifying themselves as transgender and has investigated relatively few deaths in custody.
“However, the numbers have been climbing more recently. These events made the need to address this issue all the more pressing,” he added.
He published a bulletin on lessons that could be learned from investigations into five deaths and 33 complaints between 2008 and August 2016.
Prisons house male and female prisoners separately and will usually determine gender based on that which is recognised by law.
They were allowed to request a switch if they were ” sufficiently advanced in the gender reassignment process”.
About 80 transgender individuals are believed to be in jails in England and Wales.
A Ministry of Justice spokeswoman said: “Our top priority is the welfare of those in our custody and, following a thorough review, we have taken action to improve the way we manage and support transgender offenders.
“As the Prison and Probation Ombudsman recognises, many of the recommendations outlined in his report have already been addressed but we will continue to work to improve the management of all prisoners in our custody.
“We are committed to making prisons places of safety and reform and have invested in specialist mental health training for prison officers as well as launching a suicide and self-harm reduction project.”