The Yorkshire Ripper Peter Sutcliffe is believed to have been taken to hospital.
Peter Sutcliffe, 72, an inmate at HMP Frankland, Durham City, was reportedly taken to Sunderland Royal Hospital late on Sunday evening.
Patients are believed to have seen the serial killer surrounded by guards on one of the wards at the hospital.
It is not known if Sutcliffe is still at the hospital, in Kayll Road, Sunderland.
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The former lorry driver, who was arrested in 1981, is currently serving 20 life terms for murdering 13 women and attempting to kill seven more.
One of his murder victims was Josephine Whittaker, aged 19 and he attempted to murder Olive Smelt - both from Halifax.
Sutcliffe was registered blind but is believed to have undergone laser eye surgery to save his sight at Sunderland Eye Infirmary last year.
Sutcliffe, who uses the name Peter Coonan, attacked his victims, most of whom were prostitutes who were mutilated and beaten to death, between 1975 and 1981.
He was diagnosed with paranoid schizophrenia following his life sentence but was moved to Frankland Prison in Durham from Broadmoor psychiatric hospital last year after a ruling that he was sane enough to be transferred.