A British government-sanctioned inquiry into the murder of Pat Finucane was criticised tonight by the solicitor's family after it emerged it would mostly be held in private.
Northern Ireland Secretary Mr Paul Murphy gave the inquiry the go-ahead, insisting it would be independent.
But because the inquiry would deal with sensitive matters of national security, he said much of it would be held in private.
The Finucane family claimed in a statement that the British government had conceded that the truth should emerge about the solicitor's murder.
But they insisted the establishment of an inquiry was not the end of the matter because it was not a public inquiry. "We have been asking for the truth to emerge for the last 15 years," they said.
"There is no need for new legislation to protect the public interest or national security because the current law caters for this. "Special legislation when it is needed can only mean that rather than the truth emerging, what will emerge is cover-up and lies."
Mr Finucane's son Michael claimed it appeared, contrary to Mr Murphy's claims, that the inquiry would be government-controlled.
"Effectively what we are looking at is an inquiry which is going to be established by government, accountable to government but probably controlled and restricted by government.
"Until we get to ask the Prime Minister some questions about what exactly his government proposes to do, we can't endorse or agree to co-operate with any form of inquiry.
"We simply do not know what form of inquiry this is," he added.
Earlier the British government gave the go-ahead for a judicial inquiry into the controversial 1989 murder of solicitor Pat Finucane.
Mr
Murphy confirmed new legislation would be introduced allowing an inquiry into allegations that rogue members of the Royal Ulster Constabulary and British army intelligence colluded with loyalists in the killing.
He said: "Legislation is needed, however, to provide the tribunal with the powers of the four other inquiries in Northern Ireland - Bloody Sunday, Rosemary Nelson, Robert Hamill and Billy Wright.
"Because this case deals with issues of national security, much of the proceedings will have to take place in private.
"Details will be made clear when the legislation emerges but I would suspect much of it will be in private but some may also be in public, to the extent that it can be held in public.
"Obviously that depends on the legislation and on the tribunal itself."
Mr Murphy said: "The inquiry will be independent with probably a High Court judge appointed.
This legislation will, he said, allow the inquiry "take place speedily and effectively and in a way that takes into account the public interest, including the requirements of national security".
He said the prosecution of loyalist paramilitary Ken Barrett had opened the way for the British government to establish the inquiry. The Northern Ireland Secretary added further prosecutions might yet result from the Stevens investigation into the murder of Mr Finucane.
Mr Finucane was shot fourteen times in front of his family by loyalist Ulster Defence Association gunmen in his north Belfast home.
Earlier this year, the British government confirmed retired Canadian judge Peter Cory recommended a public inquiry into claims that members of British army intelligence and the Royal Ulster Constabulary helped Ulster Defence Association gunmen to kill the lawyer.
Mr Finucane had represented republican paramilitary suspects as a solicitor in a number of high-profile cases.
But London refused to act on Judge Cory's recommendation because legal proceedings were ongoing.
Last week, Mr Barrett (41) admitted his role in the shooting and was sentenced at Belfast Crown Court to life imprisonment. He is expected to be released early under the Belfast Agreement.
It emerged, after last week's peace process talks at Leeds Castle in Kent, that the Government was planning to make its announcement on the Finucane case within days.