Image caption The six men who died: (From top left) Adrian Rogan, Barney Green, Dan McCreanor, (from bottom left) Eamon Byrne, Malcolm Jenkinson and Patsy O'Hare

Informers in the ranks of loyalist paramilitaries, involved in bringing in a huge consignment of weapons from South Africa, were protected from police investigation, NI's Police Ombudsman has said.

That is one of the stark conclusions in a report into the killings of six Catholics by the UVF in Loughinisland.

A rifle used in the 1994 massacre was part of the shipment imported in 1987.

The weapons were used in dozens of other murders and attempted murders.

The Police Ombudsman, Dr Michael Maguire, said despite being implicated in the arms plot, "senior members of the UVF, UDA and Ulster Resistance were not subject to police investigation".

He added: "This can be attributed to a decision by Special Branch not to disseminate intelligence implicating these individuals, some of whom were informants.

"It is a matter of significant concern that Special Branch failed to pass on intelligence about the alleged activities of loyalist paramilitaries, thereby protecting them from effective investigation."

Dr Maguire's report provides new and startling details about the shipment.

Image caption Part of the arms inport was seized in 1988

Surveillance

He said there was no suggestion that the weapons were deliberately allowed into Northern Ireland to protect an informer, but he raised serious questions about why only some of the weapons were intercepted after they arrived in Northern Ireland - despite Special Branch knowing all about the operation.

The report, published today, confirmed some of those directly involved in the importation of the weapons in late 1987 had been under long-term surveillance by the police and army.

When loyalists went to pick up the weapons in January 1988, they were being watched.

But the surveillance team said they lost sight of the vehicles during the actual time they were being loaded with the guns.

An hour and a half later, a substantial amount of the shipment was seized in two cars stopped at a police checkpoint in Portadown.

But not all of the weapons were seized.

Thursday's report says detectives in Portadown quickly worked out that the weapons had come from a farm because the men they had arrested had traces of manure, mud and straw on their shoes.

They tried without success to find it.

The Police Ombudsman says he established that the rest of the shipment was stored at the home of a former RUC Reservist called James Mitchell.

As part of a BBC NI Spotlight investigation, 12 years ago, I asked him to respond to allegations that he was a member of the Glenanne Gang.

The gang, which contained members of the RUC and UDR as well as loyalist paramilitaries, has been accused of carrying out 120 murders on both sides of the Irish border during the early 1970s.

Mitchell, who died 10 years ago, denied any involvement.

Image caption Weapons imported by three loyalist paramilitary groups in 1988 were used in dozens of murders

Special Branch

RUC's Special Branch knew all about James Mitchell.

Police found weapons on his farm in 1978 and in a confession he told them it was one of the main UVF arms dumps in Mid Ulster.

His farm had also been under regular surveillance by the police and army.

But Special Branch did not pass on any of this information to the detectives investigating the seizure.

The detective who led the investigation told the Ombudsman that if Special Branch had made him aware of what he knew, he would have "taken the farm apart".

Dr Maguire said: "Given the information already known about Mitchell and the fact that the detectives had been joined in one of their searches of the area by a police officer who had been present when Mitchell made his arms dump confession, I can find no logical reason why they failed to identify this property as a possible hide for these weapons."

Image caption Special Branch failed to pass on intelligence about the alleged activities of loyalist paramilitaries

Tipped off

The Ombudsman says James Mitchell was tipped off within two hours of the cars being stopped in Portadown that his farm was to be searched.

The rest of the weapons were put into a slurry tanker and moved to another hiding place that night.

Within hours, the report says, they were in the hands of a notorious loyalist killer, Robin Jackson.

A former UDR soldier, he was the leader of the UVF in the Portadown area for over two decades.

Jackson, who died in 1998, was dubbed 'the Jackal' by journalists and was behind dozens of sectarian killings.

Despite the fact that he was well known to the security forces and operated in the area where some of the weapons were recovered from the two cars, he was never questioned about the shipment.

"There is no evidence that any other senior loyalists implicated through intelligence as having been involved in the importation, nor James Mitchell, were ever subject to investigation about these events.

"Given the gravity of the conspiracy and the impact it had on the lives of numerous citizens, this decision has proven in my view to be indefensible," Dr Maguire said.