A prisoner has been charged with murder after another inmate at Garth Prison in Lancashire was found hanged five days ago.
John Hughes, 37, will appear before Leyland magistrates on Monday.
It follows the death last Monday of Kevin McCarthy, 31, who was discovered hanged in a medical ward at the jail.
Officials first thought he had committed suicide, but after information from other inmates an investigation was launched by police and Hughes was arrested.
Another inmate arrested at the same time has not been charged with any offence.