The report into the loyalist paramilitary murder of Belfast solicitor Mr Pat Finucane in 1989 has been delayed for another six months.
Metropolitan Police Commissioner Sir John Stevens confirmed today he needed time to carry out further inquiries into the shooting.
"It would be wrong to deliver the findings of this lengthy and complex investigation prematurely," he said.
Publication of findings on the role of British military intelligence and RUC Special Branch at the time of the murder have already been held up. The report was due out next month, but it will be next spring before it is ready to be handed over for examination by the Director of Public Prosecutions in Belfast.
Mr Finucane was gunned down in front of his wife and family when UDA gunmen burst into their north Belfast home in February 1989. Nobody has even been convicted of the murder.
It is understood Sir John has still to interview Brigadier Gordon Kerr, now the British military attaché in Beijing, and who was head of an undercover Force Research Unit using loyalists as double agents at the time of the killing.
Brig Kerr was running a number of senior UDA men as double agents, including William Stobie, who allegedly supplied the gun to kill Mr Finucane.
A murder charge against Stobie was withdrawn after a key witness refused to testify, and he was later shot dead by former associates outside his Belfast home last December.
Two other UDA men also questioned about the murder, Brian Nelson and Ken Barrett, both from Belfast, are living secretly under protective custody in Britain. They have never been charged.