Two men accused of plotting to kill a drug dealer have been cleared after the case against them sensationally collapsed.

Brian Roper and Paul Swann were found not guilty of conspiracy to murder Billy Webb, shot dead at his Wigan flat, on the judge's directions, following defence submissions that there was insufficient evidence against them.

Roper, 26, and Swann, 25, then changed their pleas to guilty to attempting to pervert the course of justice by providing false statements to the police.

Roper, who is currently servicng four years for conspiracy to supply cocaine, was sentenced to 18 months to run consecutively to his current sentence, which is due to expire in November.

Swann was granted a conditional discharge for two years.

Explaining his ruling to the jury, Mr Justice Hunt said that there was insufficient evidence of active participation in conspiracy to murder and that great suspicion or knowledge of something happening was not enough.

However he said Roper had given police a false alibi and also persuaded Swann, who worked for him from time to time, to support his false alibii and give a statement in his support.

Mr Justice Hunt said: "Such offences strike at the root of justice and cause great public expense. I regard it as a serious offence committed against a background of other serious offending."

He told Swann, a warehouse salesman who had spent three weeks on remand, that he was in a completely different category. He added: "I believe there to be good in you."

Two gunmen blasted Webb to death as he lay in bed beside his girlfriend at his flat in Whiteledge Road, Ashton-in-Makerfield, on May 25, 2001.

Mr Webb's girlfriend, Helen Watkinson, then 21, was badly wounded by one of the bullets.

The gunmen have never been caught and a police spokesman said today that they were still being sought.

He alleged that Roper, formerly of Thornbank, Deane, Bolton and Swann, of Basil Close, Morecambe, were part of the group which planned the killing and helped to carry it out.

Also in the dock were Roper's former girlfriend, Sarah Jane Barber, Julie Claire Hardman and Alexander Latimer.

They all denied attempting to pervert the course of justice by providing false statements to police investigating the case.

Following the developments in court, prosecuting QC Charles Garside said it was not felt in the public interest to pursue the case against the trio. Not guilty verdicts were returned.