A MURDER bid accused Greenock man facing trial over a spate of petrol and fire bombings in the town has been slashed in a targeted attack in prison.

Robert Warnock, 25, had his face ripped open by another inmate who was wielding a 'crude' razor weapon consisting of five blades attached to a piece of wood, a jail insider has told the Telegraph.

The source says that an unwitting Warnock was attacked from behind as he sat with other prisoners at a table in the main hall of HMP Addiewell in West Lothian.

Police Scotland have confirmed that officers were alerted to a serious assault having been inflicted on a 25-year-old man at the prison a week ago.

The jail insider said: "Warnock was in hospital for two or three days.

"His wound is absolutely horrific.

"The perpetrator came up behind him, grabbed him around the head from behind and very viciously, violently and aggressively drew this crude homemade five-razor weapon across his face from his ear to his mouth.

"I heard that one prison officer described it as the worst slashing he'd ever witnessed.

"It was said that the only thing that prevented Warnock's cheek from flapping down onto his neck was his lip remaining intact."

A Police Scotland spokesperson said: "Around 5.30pm on Thursday February 10, officers received a report of a serious assault taking place within HMP Addiewell.

"A 25-year-old man suffered serious, but not life-threatening injuries as a result.

"Enquiries into the incident remain ongoing."

A Scottish Prison Service spokesperson added: "We do not comment on individual prisoners. However we can confirm there was an incident at HMP Addiewell last week.

"This is subject to an investigation, so it would be inappropriate to comment further at this time."

The jail source said Warnock was attacked just two days after he had been moved to Addiewell from Shotts Prison in Lanarkshire.

The source added: "He's in the isolation wing and his face is still all bandaged up."

The Telegraph told last October how Warnock is one of a group of seven alleged Greenock petrol bombing conspirators.

They are also charged with plotting to gun down a number of men following the death of Warnock's brother.

Prosecutors say he planned from prison with his six co-accused to wreak death and destruction in Greenock and conspired to murder seven people — including a six-year-old girl.

The Crown says the gang 'did discuss the acquisition of firearms and the shooting of' two named men 'and others'.

The group are said to have committed the alleged crimes 'knowing that Reece Warnock, now deceased, brother of Robert Warnock, had been assaulted on 27 August 2019 by Leonard Cole jnr and Andrew Sutherland'.

The trial — which is set to take place later this year — is expected to last for a considerable period.