A man has been charged in connection with the attack on Peter Tobin in prison, police sources have said.
Tobin, 61, needed hospital treatment following the alleged assault in Saughton Prison, Edinburgh, at 7pm on Wednesday night. The extent of his injuries is not known.
The incident caused him to miss a second appearance at Linlithgow Sheriff Court, where he was charged with the murder of schoolgirl Vicky Hamilton in private last Thursday. The hearing was cancelled and Tobin was not discharged from Edinburgh Royal Infirmary as scheduled.
A Lothian and Borders Police spokesman said: "A 21-year-old man has been charged and a report will be submitted to the procurator fiscal."
Tobin was not expected to return to Saughton Prison on Thursday.
The body of 15-year-old Vicky was discovered at Tobin's former home in Margate, Kent, last Monday, 16 years after she disappeared.
Her father, Michael, had been at the court ahead of Tobin's expected appearance. He revealed that he had declined to have Vicky's body returned to the family in three weeks' time and was prepared to wait until the New Year to bury his daughter.
Mr Hamilton said: "I don't want to have to spend all my Christmases thinking that I buried my daughter at Christmas or just before, so we've asked the CID if we can hold it back until after Christmas and New Year."
Vicky, from Redding, near Falkirk, vanished while waiting for a bus home in February 1991. Her remains were found at 50 Irvine Drive in Margate on November 12.
She will be buried at a cemetery in Polmont, near Falkirk, her father said, and he would one day be laid to rest alongside her.
