The BBC "Panorama" program called “Britain’s Secret Terror Deals” that aired last week uncovered a rat’s nest of collusion of the British Army with IRA informers and Loyalist informers during the Northern troubles, which leaves us wondering whether we will ever know the full extent of the depravity.

No less an authoritative figure than former Ombudsman Nuala O’Loan believes that serial killers were freely allowed to operate by the authorities.

Little wonder that Amnesty International has called for a new inquiry into collusion following the revelations in the program.

The documentary was also a powerful rebuff to those who want to just 'move on' and leave the past unaccounted for. The level of officially sanctioned murder and mayhem that was revealed by reporter Darragh McIntyre was at such a level that it completely poisoned the entire British judicial and policing and military system.

Take the case of RUC constable Colleen McMurray, killed when an IRA high explosive bomb hit her police car on March 27, 1992.

It appears she was allowed to die so that a top IRA informer who helped prepare that bomb could be protected. That informer – Peter Keeley, a Catholic from Newry and also known as Kevin Fulton – infiltrated the IRA at it's highest levels in Down and Armagh.

Keeley confirmed to "Panorama" that he had tipped off the British handlers about the upcoming attack, yet nothing was done.

Former Chief Constable Sir Ronnie Flanagan has always maintained his officers knew nothing of an IRA operation in advance of the strike on Newry that killed the 34-year-old RUC Constable Colleen McMurray. She was traveling in a police car hit at point-blank range by a mortar bomb triggered by a photographic flashgun in the town’s Merchant’s Quay area.

Her colleague, Paul Slaine, lost both of his legs in the blast.

The authorities let the bombing and killing and maiming of two of their own police officers go ahead in order to save the informer.

If that smacks of burning the village to save the village consider the case of the jackal, Robert Jackson, a Mid Ulster Serial killer who killed at least 50 Catholics, though some believe the number is twice as high as that. He was never prosecuted as he was part of the Glenanne Gang run by the RUC Special Branch.

Jackson operated with impunity even after allegedly carrying out the Dublin bombings of 1974 in which 26 people were killed, including two infants. He also likely shot down the members of the Miami Showband and was a bloodthirsty murderer run by the RUC.

Panorama estimated that up to 95 percent of Loyalists arrested for murders were also working as informers. It is an extraordinary scenario and speaks volumes about how dirty the 'dirty war' was in Northern Ireland.

Time and again in the "Panorama" program (which can be viewed on the BBC website and on YouTube) when Loyalist killings occured evidence was lost, misplaced or stolen, there were mysterious fires, break-ins and, suddenly, there is no case.

It is reminiscent in a strange way of Whitey Bulger's involvement with the FBI. He too was allowed murder, torture and disappear who knows how many people with impunity long as he was a faithful informer.

"Panorama" has provided a valuable service by chronicling the incredible tale of collusion and murder that was going on. The truth can never hurt when told fearlessly.

You can watch the full documentary: