There has been wholesale collusion between security forces and loyalist paramilitaries in the North, according a report leaked to a British newspaper.
The Stevens Inquiry, set up to investigate the killing of Lawyer Mr Pat Finucane, is due to report next month but details seen by the Guardianshow the report saying "gross unprofessionalism and irresponsibility" created a situation were Catholics could be killed with virtual impunity.
It has been alleged that loyalist gunmen - including Billy Wright and Robin Jackman - were assisted by security forces in carrying out several murders of leading nationalist and IRA figures.
The newspaper says the report describes the relationship between the paramilitaries and security forces as "institutionalised collusion" but refutes any suggestion that the culture was prevalent throughout the RUC. It also says loyalist assassination squads could only have operated with the assistance of RUC Special Branch and the British army.
The inquiry conducted by London’s Metroplitan police commissioner Sir John Stevens, is highly critical of the Special Branch’s operating methods in which there was no apparent code of conduct. The failure to keep records of communication with moles and informers has also been criticised.
The paper quotes a source saying: "Next to nothing was written down, so it is extremely difficult to find out exactly what was done and on whose authorisation. Northern Ireland special branch kept no records, had no recognised policy code and yet their agents and informers were deployed at the cutting edge of life-threatening situations."
The Stevens team is expected to identify a number police and army officers and recommend their prosecution but stops short of claiming there was "policy" of collusion.
A BBC Panoramaprogramme to be broadcast next Wednesday is expected to contain further details of the Inquiry including interviews with former members of the British army's Force Research Unit (FRU) which is suspected of providing paramilitaries with information on lawyer Mr Pat Finucane.
Mr Finucane specialised in human rights cases and regularly defended republicans, including Bobby Sands.
He was shot dead by the UDA in front of his family at his home in February 1989.
There have also been more recent allegations that another high-profile human rights lawyer in Northern Ireland was also killed with the assistance of the security forces. Ms Rosemary Nelson died in 1999 in a car bomb attack.