By Peter Foster
The admission in advice to David Cameron comes after the Downing Street continues to block a judicial inquiry into the 1989 murder of the Belfast lawyer, Pat Finucane, who was a victim of the campaign, a US congressional committee was told yesterday.
Last year Mr Cameron made an apology in the Commons to the Finucane family, admitting "shocking" collusion in his murder between Loyalist paramilitaries and RUC officers but refusing a public inquiry to test claims that the killings were known and tolerated at the highest levels of government.
However, the letter written in July 2011 by Ciarán Martin, a senior security adviser written to Mr Cameron, admits that internal classified documents appeared to support the Finucane family's claims.
"[S]ome of the evidence available only internally could be read to suggest that within government at a high level this systematic problem with Loyalist agents was known, but nothing was done about it," said the letter, which also quoted a human rights sub-committee of the House Committee on Foreign Affairs.
"It's also potentially the case that credible suspicions of agent involvement in Mr. Finucane's murder were made known at senior levels after it and that nothing was done; the agents remained in place. These two points essentially aren't public."
Mr Cameron was accused of perpetuating a "massive injustice" for his continued refusal to allow a public inquiry into the murder of Mr Finucane, who was gunned down in front of his wife and children as he ate his Sunday dinner.
In a highly charged hearing on Capitol Hill, Mr Cameron was accused of seeking to protect politicians and senior British government officials who had allegedly turned a blind eye to the assassination which has remained one of the most divisive and controversial events of the Northern Ireland Troubles.
Chris Smith, chair of the human rights sub-committee of the House Committee on Foreign Affairs congratulated Mr Cameron for his Commons apology, but castigated him for its refusal to allow a full inquiry.
"The British government has reserved one final, yet massive injustice," he said, "it continues to protect those responsible for the murder of Pat Finucane." Mr Finucane's son, Michael, told the Committee that he believed the collusion with Loyalist paramilitaries "was a deep-rooted, officially sanctioned policy of selecting targets based on their degree of opposition to the State.
"The more troublesome the individual, the more likely the State was to deploy its killers-by-proxy to erase the 'problem'."
The British government had first offered a public inquiry into his father's killing in 2001 during the Northern Ireland peace negotiations but then consistently "welshed" [sic] on the commitment, Mr Finucane said.
In 2004 a review by Canadian Supreme Court Justice Peter Cory called for a public inquiry, but after repeated delays the British government agreed in 2011 to a 'review' of the case papers by Sir Desmond de Silva QC, which ruled out public scrutiny of documents and cross-examination of witnesses.
Citing a litany of previous assurances from RUC and security officials that there was no collusion -- subsequently found to be lies by the Desmond review -- Mr Finucane said his family had no reason to take British government assurances at face value.
"My family would not be permitted to see any of the documents nor would we be allowed to hear witnesses called to give evidence or ask them any questions," said Mr Finucance, arguing that the Desmond review was wholly inadequate and repeating calls for a full judicial inquiry.
The existence of the Ciarán Martin letter first emerged last month at a Belfast High Court hearing challenging Downing Street's decision not to allow a full inquiry.
The judge ordered the government to hand over minutes of the July 2011 cabinet meeting at which the decision was taken to deny a public inquiry, and correspondence between Downing Street officials and MI5.
The government has reportedly agreed to hand over the documents in chambers, however the judge Mr Justice Stephens, has insisted the material should be given to him in the court. It is unclear whether the documents, will be made available to the Finucane family.