A police killer's appeal against his "life means life" jail term has been delayed to await a European court ruling on whether such sentences amount to inhuman or degrading treatment under human rights laws.
Former United States Marine David Bieber is serving a whole life sentence for murdering traffic policeman Pc Ian Broadhurst in Leeds on Boxing Day 2003.
He has been refused permission to appeal against his conviction, but is challenging the trial judge's recommendation that he should never be freed from prison.
Yesterday, three appeal judges headed by the Lord Chief Justice, Lord Phillips, were told that the European Court of Justice in Strasbourg was due to give judgment in another case on the issue of whether jail sentences which amount to "locking somebody up and throwing away the key" contravene the European Convention on Human Rights.
Article 3 of the Convention says that no-one shall be subjected to torture or to inhuman or degrading treatment or punishment.
Adjourning Bieber's appeal, Lord Phillips said it was appropriate to await the European judgment, which could impact on all other whole life sentences being served in the UK.
Bieber, 40, a steroid abuser, shot Pc Broadhurst in the head at point blank range as he pleaded for his life.
He was also convicted of the attempted murders of two of Pc Broadhurst's colleagues.
Jailing him in December 2004, Mr Justice Moses said at Newcastle Crown Court Bieber had shown "no remorse or understanding of the brutality" of his crime.
Bieber had maintained a "cool and detached" approach when attempting to explain the evidence against him, the judge said.
He told Bieber: "You must spend the rest of your life in prison."
At the time, Bieber became one of only 25 people to have been given whole life sentences in England and Wales.
The jury which convicted Bieber was unaware that he was a suspected drug dealer who had fled to Britain from Florida where he had been questioned over a plot to hire a hitman to kill a love rival.
He was also suspected of hiring the same gunman to murder his former girlfriend, but the attempt on her life failed.
Pc Broadhurst, 34, was gunned down during a check on a stolen vehicle in Leeds.
His colleagues, Pcs Neil Roper and James Banks were shot but survived.
Yesterday's hearing was told part of Bieber's appeal was based on the argument that provisions in the Criminal Justice Act allowing an offender to be locked up without any prospect of release or rehabilitation were incompatible with human rights principles.
If European judges decide that whole life sentences are unlawful, courts will have to recall all such cases and set minimum sentences before parole could be considered.