A KNIFE offender brandished a foot-long blade at his sister-in-law and threatened to DECAPITATE her, a trial has heard.

Alan Sharp issued the chilling warning after relations between him and his extended family had deteriorated, Greenock Sheriff Court was told.

The victim had turned up at the 43-year-old's flat on Lynedoch Street in order to give a child a lift to school when he began hurling obscenities at her from his living room window.

Sharp's sister-in-law, 47, told the court: "I shouted up towards the window and all I got back was a load of abuse.

"He went away and then came back to the window with a knife and he threatened me.

"He was waving it about and shouting obscenities.

"He was saying that he would take my head off.

"I shouted back at him, 'Well, come on then'."

Sharp committed the offence from his second-floor flat on the morning of September 4 last year.

The woman estimated that the black-handled knife he was brandishing had a blade of around 12 inches in length.

She said: "I went to my mum's and had a cup of tea and told her what had happened, then I went to the police."

Sharp is married to the woman's sister.

The witness agreed with defence lawyer Edward Sweeney that relations between the family and Sharp were 'poor' at the time of the incident.

Sheriff Joseph Hughes found Sharp guilty of behaving in a threatening or abusive manner, shouting swearing, uttering threats and brandishing a knife at his sister-in-law.

Sentence has been deferred until February 26 for a background report.