Moors murderer Ian Brady faces police questioning after allegedly assaulting a nurse.
The notorious serial killer, 73, is accused of using a jug to threaten the woman on July 6 at Ashworth Hospital, Merseyside, where he is being held.
The 51-year-old nurse was said to have been left distressed and later reported the incident to bosses at the high-security hospital.
A formal complaint has been made by the nurse to Merseyside Police.
It means Brady will be questioned by officers over an allegation of common assault.
The alleged assault is not sexual and resulted in no injury.
Sources said they believed Brady had been walking along holding a jug and during the incident with the nurse the jug may have "brushed" the nurse, as Brady "gesticulates" a lot.
But Richard Nicholas, of RMNJ solicitors, acting for Brady, denied the killer had done any wrong.
Mr Nicholas said: "Ian Brady denies any improper conduct or assault."
Brady and his partner, Myra Hindley, were responsible for the murder of five youngsters in the 1960s.
They lured children and teenagers to their deaths, with victims sexually tortured before being buried on Saddleworth Moor, north of Manchester.
Hindley died in jail in November 2002, aged 60.
Brady, who has spent the last 25 years at Ashworth Hospital, has said he wants to die and is on hunger strike - but is force-fed through tubes.