State employees actively furthered and facilitated the loyalist murder of Belfast solicitor Pat Finucane but there was no over-arching conspiracy, a Government-commissioned report has found.

Sir Desmond de Silva's review of the 1989 murder of the Catholic father-of-three found collusion by the state went beyond a failure to prevent the crime. Sir Desmond examined the role of two British agents in the murder and found another man involved was later also recruited as an agent, even though he was suspected in the UDA murder of Mr Finucane.

While the QC accused successive UK governments of a "wilful and abject failure" to implement an appropriate legal framework for running agents within paramilitary groups, he said no minister was aware of the plot to kill the solicitor.

Prime Minister David Cameron told the House of Commons the murder was "an appalling crime" and said the degree of collusion exposed was "unacceptable". I a message to the family, Mr Cameron said: "I am deeply sorry."

Mr Cameron told MPs the de Silva report highlights "shocking" levels of state collusion. The Army and Special Branch had advance notice of a series of planned UDA assassinations, but nothing was done, he said. Mr Cameron said De Silva found that employees of the state and state agents played "key roles" in the Finucane murder, adding: "It cannot be argued that these were rogue agents."

The review found that the Army must take a degree of responsibility for targeting activities carried out by the UDA's Brian Nelson, said Mr Cameron. There was a "relentless" effort to defeat the ends of justice after the killing and Army officials provided the MoD with highly misleading and inaccurate information, Mr Cameron said. But the review found no evidence that any Government was informed in advance of Mr Finucane's murder or knew about the subsequent cover-up, he said.

Mr Cameron said the Finucane family suffered "the most grievous wrongs" and he respected their view that the de Silva review was not the right response. But he said he disagreed with them, and said a public inquiry might not have uncovered so much information about the killing.

In a statement to the House of Commons, Mr Cameron said: "The collusion demonstrated beyond any doubt by Sir Desmond - which included the involvement of state agents in murder - is totally unacceptable. We do not defend our security forces - or the many who have served in them with great distinction - by trying to claim otherwise. Collusion should never, ever happen. So on behalf of the Government - and the whole country - let me say once again to the Finucane family, I am deeply sorry."

Labour leader Ed Miliband urged the Prime Minister to launch a public inquiry into the killing. Mr Miliband told the House of Commons that Labour had begun to set up a public inquiry - which was recommended as a result of the Weston Park agreement between the British and Irish governments in 2001 - before it lost the last general election in 2010.He said the coalition's failure to press ahead with a public inquiry was "at odds" with the peace process.

But Mr Cameron said: "History of public inquiries in Northern Ireland would suggest that, had we gone down this route, we would not know what we know today." The three full criminal investigations carried out by former Metropolitan Police Commissioner Lord Stevens amounted to "the biggest criminal investigation in British history", he said. Mr Cameron said he had asked Defence Secretary Philip Hammond, Northern Ireland Secretary Theresa Villiers and Cabinet Secretary Sir Jeremy Heywood to report back to him on issues arising from the report, and promised to publish their responses.