An investigation has been launched after a transgender inmate was found dead in her cell at an all-male prison.
Jenny Swift, a prisoner at privately run HMP Doncaster, was discovered unresponsive at 12.40am on December 30.
Staff and paramedics attempted CPR but she was pronounced dead at 1.10am, the Prison Service said.
Swift, 49, from Seaforth in Sefton, Merseyside, was charged with attempted murder after Eric Flanagan, 26, was found with multiple stab wounds in Balby, Doncaster, on November 15.
She was remanded in custody at Doncaster Magistrates' Court two days later. Mr Flanagan died a month after the incident.
An unnamed friend claimed Swift had asked to be put into a women's prison, the Sheffield Star reported.
HMP Doncaster is a category B prison operated by Serco which houses a male population of up to 1,145.
The Prisons and Probation Ombudsman confirmed an independent investigation has begun.
A spokeswoman said: "We will be in contact with Ms Swift's family and will try to address any questions they may have.
"Our independent investigation will aim to identify the full circumstances of the death and whether there were any failings in Ms Swift's care.
"Where possible we will identify lessons to be learned and make recommendations to help prevent similar deaths in future.
"We also share any findings with the Coroner to assist with their inquiries."
The Ministry of Justice launched a review of the care of transgender prisoners after the deaths of two inmates at all-male prisons.
Vicky Thompson, 21, was found dead at HMP Leeds in November 2015, and Joanne Latham died at HMP Woodhill in Milton Keynes in the same month.
The review, which was published in November, revealed that one in four prisons in England and Wales holds at least one transgender inmate.
Data collected in March and April showed that 33 of the 123 public and private prisons reported they had one or more transgender prisoners.
There were 19 establishments with one transgender inmate, 10 with between two and four, and four holding at least five.
The review said: "It is apparent that the treatment of transgender people in courts, probation and prison services has not kept pace with the development of a more general understanding of the issues surrounding gender in society."
Detective Chief Inspector Vicky Short said the investigation into Mr Flanagan's death continues.
She said: "On Friday 30 December, we were made aware that the person charged in this investigation had died. However, the inquiry into Mr Flanagan's death remains ongoing at this time and his family continue to be supported by officers."