Pat Finucane was shot dead by loyalist paramilitaries
An inquiry is to be held into the murder of Belfast solicitor Pat Finucane, the British Government has said.
It said a tribunal would be tasked with uncovering the full facts of what happened in north Belfast in 1989, with all the powers and resources for that job.
However, the government said because of national security requirements, new legislation would have to be introduced before the inquiry begins.
But the Finucane family said new laws were not needed and could only mean that rather than the truth emerging, what would emerge was "cover up and lies".
Mr Finucane, 39, was shot dead in front of his family at his home by the loyalist Ulster Defence Association.
The killing was one of the most controversial of the 30 years of the Troubles in Northern Ireland, mainly because of the allegations of collusion between loyalist paramilitaries and members of the security forces.
Details of an inquiry into his murder were given by Northern Ireland Secretary Paul Murphy in London on Thursday.
He said the inquiry would be both public and private but that the government was determined that, where there were allegations of collusion, "the truth should emerge".
Mr Murphy added: "The government has taken into account the exceptional concerns about this case.
"Against that background, the government has concluded that steps should now be taken to enable the establishment of an inquiry into the death of Pat Finucane."
However, Mr Finucane's son Michael said he had a "serious concerns" about what the government was recommending.
"What we're looking at is an inquiry that's going to be established by government, probably accountable to government, but also controlled and restricted by government," he said.
Michael Finucane: Family have serious concerns
"That...is about as far from an independent tribunal of inquiry as you can get. What Mr Blair is proposing is a government investigation not a public inquiry."
He said the government had conceded for the first time that the truth was necessary and that there were exceptional concerns about the case.
"But yet they cannot make the simple confirmation that the examination of the issues will happen in public and will be independent," he added.
Mr Finucane's widow Geraldine said the family may not participate with the inquiry, if they do not agree with its terms of reference.
The family is to meet the prime minister next month to reinforce their demand for full disclosure of "all security force foreknowledge of the killing".
Reacting to news of the inquiry, Sinn Fein's Mitchel McLaughlin said: "The track record of successive British Governments in dealing with the issue of collusion and specifically the killing of Pat Finucane, has been one of denial, concealment and cover-up.
"Any inquiry, and the legislation it will be based on, will be judged against its ability to uncover the full truth about collusion and the killing of Pat Finucane."
SDLP leader Mark Durkan said his party would continue to press for a public inquiry into the murder, as it raised concerns about collusion and cover-up.
"These issues cannot be addressed by an inquiry which itself could be shrouded in collusion and cover-up," he said.
Retired Canadian Judge Peter Cory was appointed by the British and Irish Governments to examine allegations of collusion surrounding the Finucane and other controversial killings.
He recommended a public inquiry into Mr Finucane's death.
Loyalist Ken Barrett, 41, was sentenced last week at Belfast Crown Court to life for Mr Finucane's murder, after admitting his part in the killing.
However, he could be freed within months under the terms of the Good Friday Agreement.
He was the first person to be charged with the solicitor's murder.
The Finucane family said they were not particularly interested in convictions, and that Barrett's guilty plea served to conceal the truth that could only emerge at a public inquiry.