A sex pest with a 24-year history of exposing himself to women is facing jail after being found guilty of committing a sex act in public.

Oxford Magistrates' Court heard today that John Bustin, who has convictions dating back to 1984 and was given an Antisocial Behaviour Order in 2006 in a bid to stop him flashing, committed the sex act in front of a woman in an alleyway.

Bustin was identified by his victim after she saw his picture in the Oxford Mail a month after the incident last July.

The 41-year-old - who was pictured in a report about people issued with Asbos - was also found guilty of breaching the terms of his order, which ban him from exposing himself in public places.

Gail Marriner, prosecuting, said Bustin, of Speedwell Street, Oxford, stood in the alleyway off Osney Lane, and refused to move when his victim and her friend tried to walk past.

Ms Marriner said: "When they reached the end of the alleyway she turned around and saw that he had pulled his trousers down."

The woman, who cannot be named for legal reasons, said: "He looked a bit unsteady on his feet and I thought he could have been drunk. The man was very edgy and acting strange.

"When I looked back, I could clearly see him through the bars of the alleyway.

"The gentleman's trousers were down by his thighs. He clearly looked at me and he wasn't ashamed that I had seen him and he carried on."

Describing the moment she saw his photograph in the Oxford Mail, she said: "I looked at the picture and I thought it was him immediately. His face was the same as the man I had seen."

Bustin denied exposing himself and said although he could not remember what he was doing at the time, he was probably watching TV.

Nick Cotter, defending, said Bustin's flashing dated back to 1984 and he had been jailed several times.

He said: "In more recent times it has been custody, custody, custody and more custody. It hasn't stopped Mr Bustin from reoffending.

"These are matters where he cannot be locked up for all that long until he has his liberty again."

Aubrey John, the presiding magistrate, told Bustin: "We believe the victim's statement was credible and we believe it because of the proximity of the witness to you and the time she had to observe you.

"We have decided that the offences you have committed are so serious you should receive greater punishment than we can give you at this court."

Bustin was granted bail on condition that he reports daily to the police until he appears for sentencing at Oxford Crown Court on Monday, April 21.