A 17-member inquiry team headed by incoming Metropolitan Police Commissioner Sir John Stevens has obtained new evidence supporting allegations of collusion between the Royal Ulster Constabulary (RUC) and Loyalist paramilitaries.

Police believe they have identified a six-man terrorist gang that carried out the shooting of Catholic civil rights lawyer Pat Finucane in 1989. The evidence has been sent to the Director of Public Prosecutions naming three loyalists as the hit men with three more acting as a backup team.

Stevens had headed a similar inquiry at the time of the killing, which uncovered links between loyalist paramilitaries and the British army. The findings of that inquiry were kept secret and only came to light some years later. Stevens was called in to start a fresh investigation last April as demands for a public inquiry mounted.

While Stevens's efforts focus on the possibility of “rogue” officers from the RUC and Army intelligence colluding with loyalist death squads, for 10 years human rights campaigners have insisted that the collusion goes to the very heart of the RUC itself. The Finucane family has refused to co-operate with the Stevens team, insisting that only an independent pubic inquiry, which excludes the RUC from conducting any of the investigations, will bring out the truth about this and other killings.

Police officers have obtained DNA samples from at least one murder weapon and a Balaclava helmet worn by one of the killers. A number of tape recordings in RUC possession have also been located. Witness accounts and forensic material is said to support claims that the RUC failed to prevent the killing, despite being warned in advance by at least two informers.

Of the six men identified by the investigation, two are accused of firing 13 shots into Pat Finucane at his family home in West Belfast. A third man is said to have driven the getaway vehicle. The evidence suggests that a backup team of three more men were waiting in a car near the Finucane home, giving some indications of the importance assigned to the operation.

Finucane was most probably targeted because he had acted as defence counsel to a number of Republican suspects. Last year another lawyer, Rosemary Nelson, was killed in a car bomb following the public stance she had taken to demand an inquiry into RUC collusion in the Finucane murder. Prior to her death, Nelson had said that she had received death threats via her clients after they were interrogated by the RUC.

One of the first actions of the new investigation was the arrest of William Stobie, a self-confessed member of the Ulster Defence Association (UDA), who was charged in the Finucane murder. At a remand hearing, Stobie insisted that he was a registered informer for the RUC Special Branch at the time of the Finucane murder, and that he had phoned his police handlers twice to tell them an unnamed "top Provie" was going to be shot.

The inquiry team is said to have found evidence supporting Stobie's claim, including statements from previous informers and former RUC officers. Fingerprint and DNA evidence from tapes and papers kept by the RUC and Army, and obtained by forensic experts, links Stobie with certain security handlers as well as loyalist terrorists.

Stobie's claims were given added credibility when respected Irish journalist Ed Moloney published an interview he had conducted with Stobie at the time of the Finucane murder. Stobie explained how, as a UDA quartermaster, he was responsible for providing the weapons to be used in the killing. His warnings to the RUC were ignored and no action was taken to prevent the assassination. Moloney revealed how all of this was known to the RUC for at least 10 years.

The issue of RUC collusion in the Finucane murder refused to go away and became intimately bound up with the Northern Ireland "peace" process, under which policing was to be the subject of a major review.

Commenting on the new evidence, the Independent newspaper in Britain said that the "findings come at a highly sensitive time for policing in Northern Ireland after the Government announced implementation of the Patten report into the future of policing. The handling of the Finucane case over the 10 years is cited by critics as an illustration of why far-reaching change is necessary."

However, demands for the disbanding of the RUC have been largely ignored by the British government in favour of cosmetic changes such as renaming it the Police Service of Northern Ireland and removing the crown from the RUC badge. The new evidence highlights just how mild the proposed RUC reforms are given the force's history in enforcing the sectarian divide.