A man's conviction for murder almost 35 years ago could be overturned after it was referred to the Court of Appeal.
Officials at the Criminal Cases Review Commission (CCRC) confirmed the case of Errol Heibner will be re-examined.
They said new information about a confession by Heibner and a key trial witness meant there was a "real possibility" that the verdict might not be upheld.
Heibner was convicted at the Old Bailey in November 1976 of the contract killing of Beatrice Gold.
Mrs Gold was shot dead the previous year in the basement office of the clothing business she ran with her husband in Clerkenwell, east London.
Heibner told The Guardian: "It has been a very long road. I have fought very hard for this but, from day one, I have always believed that it would be referred back eventually. I am obviously very happy that it has finally happened."
His solicitor, Rhona Friedman, who applied to the CCRC in 2002, said her client has always protested his innocence.
He has been supported by the Lord Ramsbotham, the former Chief Inspector of Prisons, and the Reverend Nicholas Stacey, former Chaplain at Maidstone Prison.
Ms Friedman said: "This is perhaps the last of the 1970s police corruption cases left unexamined by the courts and represents an extraordinarily murky episode in our criminal justice system.
"We hope that the Court of Appeal will shine a light on what has gone on and that finally this miscarriage of justice will be put right."
Heibner was jailed for life with a minimum tariff of 25 years and was recently released from prison.
His first attempt to appeal against his conviction was refused in 1978. A review of the case was undertaken by Scotland Yard but no further action taken.
A second application for a review was made to the Home Office in 1992 and a second Metropolitan Police inquiry took place. Again, no further action was taken.
Heibner's case was reopened by the Commission in 2007, five years after his solicitor first approached the organisation.
A CCRC spokesman said officials considered the validity of Heibner's original confession and new evidence about a key witness.
He said: "Having considered a range of issues, including the admissibility and treatment of confession evidence at trial, and new evidence relating to a witness at trial, the Commission is referring the conviction to the Court of Appeal because it considers that there is real possibility that the court may not uphold the conviction."