Murderer and rapist Adrian Bayley has been attacked inside Barwon Prison, with sources confirming that the notorious killer of Jill Meagher was stabbed by another inmate on Thursday.

Bayley is understood to have been stabbed with a fork and suffered minor injuries during the altercation.

The 46-year-old has spent much of the past five years in protective custody because of concerns he would be targeted by other inmates.

He is serving life in prison for the 2012 rape and murder of Ms Meagher and raping two other women. He will be eligible for parole in 2055, when he is 83.