Bradford killer Keith Downey was on the run today after slipping away from prison guards while on a parole trip.

And today police warned members of the public not to approach him because he could be dangerous.

Downey was convicted in 1986 of murdering his brother's gay lover by strangling him and stabbing him with a pair of scissors.

The 35-year-old, originally of Ayerson Oval, Allerton, was given a life sentence but was nearing the end of his term in prison.

He was on a 'familiarisation' trip aimed at helping prisoners prepare for life on the outside when he managed to escape his guards in Birmingham city centre close to the railway station.

Ports were immediately put on alert and Downey's photograph was circulated to ports and other forces, while 50 West Midlands police officers joined a manhunt in the city centre after the alarm was raised at 1pm.

Later a police inspector was forced to admit that the fugitive "was probably long gone."

A Home Office spokesman said the Prison Service had launched an investigation into how Downey had escaped.

He had been locked up at Featherstone prison, Wolverhampton, where he was a category C prisoner - the lowest is category D. He would not have been handcuffed during the trip and was in plain clothes.

"The familiarisation visits are for prisoners who have been in prison for a while and are nearing their release," said the spokesman.

"It aims to prepare them for life back in the community and is a carefully managed programme."

Downey is described as white, 5ft 4ins, stocky, with receding short, dark hair and a goatee beard.

He was wearing dark blue jeans, a black sweatshirt and blue and white trainers. He is said to speak with an accent common to the Nottingham and Mansfield areas.

He was last seen near the Pallasades shopping centre in Birmingham at around 1pm yesterday.

Inspector Mick Pearson, of West Midlands Police, said: "We are contacting relatives as an obvious first port of call. He is a Midlander and he knows the Birmingham area well. We have circulated his picture everywhere, so a lot of people should know what he looks like."

Insp Pearson said Downey had been due to transfer to an open prison, but did not yet have a release date. I think it's fair to say he isn't likely to be going to an open prison now," he added.

Downey was convicted of murdering David Murray, 41, by strangling him with a scarf and stabbing him with a pair of scissors.

The trial at Leeds Crown Court in 1986 heard Mr Murray had had a homosexual affair with Downey's brother, Roy, which disgusted Downey.

He took Mr Murray drinking and after returning to Murray's Allerton flat killed him.

Murder hunt detectives eventually tracked Downey down to an address in Birmingham after acting on a tip-off.

At the time of his trial he told the jury at Leeds that he had not pre-planned the murder.

But the jury found him guilty of the pre-meditated killing of Mr Murray.

They were also told how Downey and his brother Roy had even returned to Mr Murray's Allerton flat and stolen the dead man's stereo and video recorder.

Mr Murray was 5ft 4ins tall, slim with grey hair combed back and worked on the domestic staff at Lynfield Mount Hospital in Bradford.

Neighbours described Mr Murray as a good Samaritan who was always willing to help out.

"He would speak to anyone. He seemed very easy to get on with and was usually bright and cheerful," one neighbour said at the time of his death.