A top-security prisoner ended his chances of early parole by threatening to kill a guard and his family, a court heard yesterday.

Keith Pringle, 33, was jailed for 15 years in 1992 after holding his ex-girlfriend at gunpoint in her Darlington home for 48 hours.

The siege was only brought to an end when a police marksman was brought in, who shot Pringle.

After serving more than ten years of the sentence, Pringle, of Thirlmere Road, Darlington, could have been released later this year.

But, flanked by eight prison officers in the top security dock of Newcastle Crown Court last month, he pleaded guilty to making threats to kill Frankland guard Paul Sirrell, his wife and children.

Mr Sirrell had been one of five officers who entered Pringle's cell during a "dirty protest" on September 10 last year when the threat was made.

He was sentenced at Newcastle Crown Court yesterday to a further three years.

Judge Guy Whitburn complimented Pringle for entering a guilty plea, so that the six-week trial date booked for later this year could be scrapped.

Barrister Jamie Adams, for Pringle, told the court: "He is looking to get out as quickly as he can."