The jury in the York murder trial have heard details of an attack that the prosecution claims killed father-of-five Mark Webb.

The jury also heard allegations that the dead man’s wife, Susan Webb, co-ordinated a cover-up to protect the alleged murderer while on the phone to police, and told an eyewitness to lie to officers about what happened between her new partner, Brian Cox, and her husband.

Witness Kerry Munton told Leeds Crown Court she saw Cox, who had lived at her house for a few weeks, hold Mark Webb against an alley wall near her house in Stuart Road.

“Mark tried to push him away and he couldn’t move, and then after that, that is when I saw like a fast striking action coming down, like, on Mark’s neck,” she claimed. As she did, she made a diagonal movement with her hand starting at elbow height, coming downwards.

“Brian ran away. Mark turned down the alley and staggered off,” she alleged. “I noticed there was blood. He was bleeding into his top but I couldn’t see beneath the bomber jacket he had on. You could see it had come from his neck.”

Describing the scene afterwards, she said: “There was a big pool of blood. There were big blood splashes down the wall.”

She claimed she later saw the blade of a Stanley knife on the ground and said she later heard Susan Webb say “we had better clean up the blood before the police get here, so we can say he had done it himself.”

Cox, 29, denies murder. Susan Webb, 30, of Middleton Road, Acomb, and Dawn Coates, 49, of Chapel Terrace, Acomb, both deny perverting the course of justice.

Ms Munton claimed she was in her back garden at about 4pm on March 4 when Mr Webb, who had been drinking, came to her house demanding to see his children, who were inside. She refused to let him in.

She alleged Susan Webb had told her he had been violent towards her when drunk. Susan Webb shouted abuse at Mr Webb, Mr Webb had tried to get in, Cox had come out to stop him and the two men had struggled, ending up in the side alley.

Ms Munton claimed after he ran off, Cox rang Susan Webb’s mobile and Ms Munton answered because the wife was talking to police on the house phone at the time.

She alleged she relayed Cox’s message that he was going to hand himself in to police and Susan Webb said twice “no he isn’t”.

After the mobile phone conversation ended, but while she was still talking to police, Susan Webb told Ms Munton to ring Cox back and tell him the two women would cover up for him. Ms Munton alleged in a separate conversation, she told Susan Webb that Cox had cut Mr Webb’s throat and they should call an ambulance.

“She said no, I will do that. I will go and make sure he is all right in a bit.”

Susan Webb then took bleach, hot water and a dustpan and brush and went outside to clean up the blood. When she returned, she took a Stanley knife out of her pocket, alleged Ms Munton.

Asked how she felt about telling everyone Mr Webb had injured himself, Ms Munton claimed she went along with it because she was “scared and worried” about what Susan Webb would do.

She claimed she told Cox during a phone call she would not lie for him.

Cox later returned to the house and was arrested.

The trial continues.