A man revealed he was a convicted killer while threatening to stab a betting shop manager, a court heard.

Matthew Stubbs told Melanie Nicholson he had "done time for murder" and would "slit her open", it is alleged.

A jury at Bradford Crown Court was played a tape of a 999 call from Mrs Nicholson in which Stubbs is heard loudly demanding his winnings.

Mrs Nicholson told the court she was working alone at William Hill, on Manchester Road, Bradford, at 8.50pm on August 10 last year when Stubbs came in.

She said he was very agitated, swearing and talking to himself. When he lost £20 on a gaming machine, Mrs Nicholson alleged he accused her of rigging it.

She told the court she asked him to leave after he refused to moderate his language.

She also warned him that if he got a winning ticket she would not pay him. When he won £30 and she refused to give him the cash, he tried to fit his upper body under the "bandit" security screen.

The jury watched silent CCTV footage of Stubbs, in a striped top, brandishing his winning ticket at a security camera. Mrs Nicholson alleged he was saying: "I'll knife you. I'll wait for you. I'll get life."

She said Stubbs, 30, threatened to lie in wait for her. "He said he had done time for murder before and he was going to kill me, stab me. He said I'll be waiting for you'," Mrs Nicholson said.

She said his carrier bag banged against the counter with a metallic sound and she "firmly believed" he had a knife. She said he punched a gaming machine, repeatedly kicked the counter door and damaged a till.

She claims he tried to incite a group of up to 17 youths hanging around outside to "trash the shop" before the police arrived.

Stubbs denies affray and criminal damage at the bookmaker. He also pleads not guilty to witness intimidation at William Hill, in John Street, Bradford, on March 6 this year.

Mrs Nicholson alleges Stubbs came into the city centre branch, where she transferred in January, and shouted that she had tried to "fit him up".

She said she found out last November that he was to be charged with the August incident and was given his name.

On February 26 she saw an article in the Telegraph & Argus in which Stubbs said he had a conviction for killing someone. She told the jury this surprised and worried her.

After Stubbs came into the John Street shop she felt "very frightened, intimidated and vulnerable". She told the jury she was physically sick when he left.

Mrs Nicholson agreed she was convicted by magistrates of deception and theft on December 13, 1993, and sentenced to a probation order.

Defence barrister Richard Wright suggested to Mrs Nicholson that all Stubbs was doing in August 2006 was demanding the money he won on the machine.

The trial continues.