Actor Ray Winstone has claimed there was an "outrageous miscarriage of justice" after an innocent man served seven years in jail for a murder that he did not commit.
Sam Hallam, 24, was found guilty of murdering Essayas Kassahun in 2005 but has now been freed by the court of appeal.
Winstone, the uncle of one Hallam's friend, spoke outside after the judgment was delivered: "So why did an innocent man serve seven years?
"For me it is the disgraceful, unprofessional action of the police involved in this case. Action that has caused a terrible stress within the family of the Hallams."
The Scum star added that his conviction had torn apart the Hallam family, leading Terry Hallam, Sam's father, to commit suicide. He was found hanged in October 2010.
In a statement, Winstone said that Hallam, of Hoxton, north London, was in fact nowhere near the scene of the crime, was not captured on CCTV and there was no evidence to say he was the killer.
"Someone must answer for this outrageous miscarriage of justice," the actor said.
"A young man lost his life. His family will never get over that.
"The killer is out there because the police involved in this case did not do their job.
"Who will answer for this miscarriage of justice?"
Hallam was given bail after the prosecution said they would not oppose his appeal against his guilty verdict.
Kassahun, 21, died in a gang attack in Clerkenwell, central London, in October 2004.
The judge in the case, Lady Justice Hallet, is now due to deliver a fresh verdict at the appeal court.