Two charged over Frankland prison murder
A 32-year-old man and a 23-year-old man will appear before magistrates on Monday, police said.
Harrison, from Wolverhampton, was jailed in 2009 after raping a 13-year-old-girl in Cumbria in 2009.
A Durham Constabulary spokeswoman said: "The man who died can now be named as Mitchell Dean Harrison, whose last address was in Cumbria.
"Two men, aged 32 and 23, have been charged with murder and will appear before Peterlee magistrates on Monday."
Harrison was given an indeterminate sentence at Carlisle Crown Court in January last year after being convicted of the raping the teenager.
He was sentenced to at least four-and-a-half years in jail and was put on the sex offenders register for life.
Frankland holds more than 800 of the most serious offenders in the prison system.