The historical enquiries Team (heT) had an impossible task from day one, former police ombudsman Nuala O'Loan has said. hMInspectorate of Constabulary (hMIC) fouwnd last week that the heT - set up in 2005 to re-examine 3,260 murders during the Troubles - has investigated cases where the state was involved with "less rigour" than others.
In a damning report, it said the approach was inconsistent and had serious shortcomings, prompting the Policing Board to say it has no confidence in the leadership of the unit.
Speaking on the BBC's Sunday Sequence programme yesterday, Mrs O'Loan said that 15 years since the Good Friday Agreement "we haven't brought any sort of coherence to this question of dealing with the past".
"The problem with the heT was that it never had investigation powers. It never had police powers. All it was established to do was to look at cases and that was a problem," she said.
"What we need to do is to take the police ombudsman's historic cases and all the police's historic cases and locate them in one single investigation unit and that would be part of the work of a legacy commission.
"It should have full police powers and be properly funded and should be completely independent from the police."
She said the shelved James-Bradley report from 2009 was "the best show
in town" in terms of dealing with the legacy of the Troubles.
"The only show in town for me is the legacy investigation process - one single unit fully powered and fully resourced with no time constraints on it," she said.
"The establishment of the heT was [then PSNI chief constable] hugh Orde's response to a desperate situation.
"I knew that he had such a limited remit -- it had no powers -- that it had an impossible task. It was supposed to be 40 cases a week... To my mind it was never ever going to produce a result."
Meanwhile, former victims commissioner Patricia McBride said on the programme that UUP leader Mike Nesbitt had never opposed the idea of a conflict resolution centre at the site of the former Maze prison when he was also a commissioner.
"So it was a shock to me to hear Mike Nesbitt making statements using language like 'innocent victims' which is divisive and not the type of language that he would have used as victims commissioner, nor would it have been acceptable for him to use it," she said.
Mr Nesbitt and the DUP's Peter Robinson exchanged open letters last week over the peace centre, with the UUP leader arguing it should not be sited at the Maze because of opposition from victims.