A FACTORY worker held a knife to his girlfriend's neck and locked her in their home before threatening to blow up it up, a court has heard.

Keith Andrew Allison, 44, was said to be upset about an alleged theft he was accused of and wanted to talk to his girlfriend of three years about it.

On Monday morning Allison went to her workplace at Tesco in Newton Aycliffe, before eventually finding her at the home they shared on Baliol Road in the town.

At the weekend Allison had moved out of the house to stay with his brother after the alleged theft caused problems with the relationship. Yesterday, Blair Martin, prosecuting, told Newton Aycliffe Magistrates' Court: "The defendant has spoken to the injured party, he pulled out a Stanley knife and he has held it to her throat and threatened to slit her throat."

Allison claims the blade of the knife was not extended when he had it to his girlfriend's throat, but she was unaware of that.

He then locked all the doors of the house and prevented her from escaping the ordeal.

Shortly after 8.25am, she left the house and raised the alarm with the police, who sent an armed response team and a negotiator to the address.

Meanwhile Allison, who works for ThyssenKrupp Tallent in Newton Aycliffe, turned on all the gas rings on the cooker and shouted to police: "If anyone approaches the house it will go bang."

After a short stand-off, Allison handed himself in to police, who arrested him at about 8.50am. Gas engineers were called out to make the home safe.

Sam Brewster, defending, said: "This strikes me as a bizarre case because clearly the defendant has behaved in a serious way, but a way which is alien to his character and it is something which at the moment he can't understand or explain.

"He is an extremely mild-mannered man.

"Whilst this was going on he felt as though he was someone else. What happened yesterday was some sort of aberration of this man's mental health. A psychiatrist will have to see him to say what happened yesterday."

Allison pleaded guilty to false imprisonment, threats to kill and threats to damage or destroy property. Mr Brewster said the alleged theft was a minor incident and would not be dealt with by the police or the courts. He will appear next at Durham Crown Court on June 30.