is said to be 'gravely ill' after refusing treatment for coronavirus.He spent five nights in hospital but was returned to HMP Frankland in Durham on Monday.Now the sister of a woman thought to have been murdered by Sutcliffe has called on the serial killer to tell them the truth.Gloria Booth, 29, was strangled and dumped in a park in 1971.Her family are convinced Peter Sutcliffe was the culprit.