Britain’s justice ministry said he had died in hospital. “As with all deaths in custody there will be an investigation by the independent Prisons and Probation Ombudsman. Our condolences are with Mr. Clifford’s family at this difficult time,” a prison service spokeswoman said in a statement.

The BBC said it understood that the 74-year-old had collapsed in his cell on Thursday while trying to clean it, then again the following day.

Clifford’s conviction in 2014 was the first from an inquiry into historical sex abuse triggered by reports that the late BBC TV presenter Jimmy Savile had been a prolific sex offender for decades.

Clifford, whose clients had included TV music mogul Simon Powell and U.S. boxer Muhammad Ali, was found guilty of eight counts of indecently assaulting four girls aged 14 to 19 between 1977 and 1984.

He had denied all charges, saying the allegations were “utterly repulsive” lies by fantasists and opportunists.