An inmate has been charged with murder over the death of convicted child sex offender Ashley Bropho at Perth's Hakea Prison.
West Australian police launched a homicide investigation after Bropho, 40, was found unresponsive in his cell on March 9.
Prison staff provided first aid and paramedics attended but he could not be revived.
Police on Thursday said a 42-year-old sentenced prisoner had been charged with Bropho's murder.
He will appear in Armadale Magistrates Court via videolink from custody on Friday.
Bropho, who had an intellectual disability, had been awaiting sentencing in the District Court earlier this month after pleading guilty to abusing a nine-year-old girl he lured back to his Doubleview home from a nearby park.
He had been living under the supervision of an NDIS carer in July last year when he committed the sexual offences that led to his imprisonment.
WA's prison officers union earlier this month said tensions had been rising at Hakea for several months, with overcrowding and understaffing "frequently reported".
