Sam Hallam, who has served seven years for murder, is to be released from prison on Wednesday after the prosecution told the court it would not oppose his appeal.

In a dramatic moment at the court of appeal, 24-year-old Hallam was told that he would be released. Jailed in 2005 for the murder of Essayas Kassahun he has always protested his innocence and his family and friends have campaigned fiercely for his release.

The Metropolitan police face criticism for their murder inquiry and were accused in court of failing to disclose evidence and failing to pursue lines of inquiry.

Supporters and Hallam's mother, Wendy, wept in court, and outside scores of friends from Hoxton in north London repeated: "We just can't believe this."

Hallam ? who was 17 at the time ? was convicted in 2005 of murdering trainee chef Kassahun in Hoxton in October 2004. He was sentenced to life with the recommendation he serve 12 years.

But his family and friends, including the actor Ray Winstone, have campaigned to have his case reopened for a number of years.

After Hallam failed to have his conviction overturned at his first appeal, his case was referred to the criminal cases review commission, which spent three years examining the evidence. It instructed Thames Valley police to carry out inquiries on its behalf, which involved examining the whole of the original Metropolitan police murder investigation.

Kassahun, 21, had come to the aid of a friend, Louis Colley, who was being attacked on Old Street, in central London, by a mob of youths over a trivial perceived insult.

Hallam was convicted on the basis of disputed identification from two witnesses who placed him at the scene of the killing. In his defence, Hallam claimed he was playing football with a friend at the time. He said he knew there was going to be trouble on the night of the killing as a mob set off to look for Colley and had wanted to avoid it.

One of seven charged with the murder, Hallam initially, on the advice of his lawyer, declined to answer police questions, something his supporters claim may have counted against him at the trial.

Another man, Bullabeck Ringblong, was also convicted of the murder and is serving life. The trial judge recommended Hallam, who is in HMP Bullingdon, should serve a minimum of 12 years.