A former detective sergeant has denied at the Smithwick Tribunal that he was an IRA source and that he helped the subversive organisation.

However, Owen Corrigan acknowledged that he did not assist other colleagues in passing sources or intelligence to them and that he failed to pass on information about lives being threatened by the IRA when a smuggler was abducted, tortured and killed.

After the Anglo Irish Agreement in 1985 the number of detectives in Dundalk swelled from ten to 40 and Mr Corrigan said he was sidelined and ignored by senior officers.

Under cross examination by Mark Robinson, counsel for the PSNI, the witness accepted he did not pass on his intelligence or expertise to other detectives but said there was a detective sergeant there nearly as long as he had been.

Mr Corrigan compared the new regime in Dundalk Garda Station at that time to a "vampire's den."

The witness also said that he did not pass on any of his sources of intelligence about republicans to other detectives before he left the force.

It was put to him that by his actions he had impeded the flow of intelligence to An Garda Síochána, but Mr Corrigan replied that it was up to every garda to get their own sources.

After he was sidelined in the wake of the Anglo Irish Agreement, Mr Robinson put it to him that "you were ripe for the picking to become a source."

The witness rejected that saying it was an insult to his integrity.

"Given your position, knowledge and contacts you were the perfect source for PIRA," said Mr Robinson.

"I was not and I find that statement deeply offensive," replied Mr Corrigan. He said he spent his career saving lives.

The witness claimed he was largely responsible for bringing the IRA bombing campaign in Belfast to an end following his work in discovering a large IRA bomb making factory south of Drogheda where 3.5 tonnes of explosives were found.

Mr Corrigan also said he believed his life was still under threat because DUP MP Jeffrey Donaldson had named him in the House of Parliament as being an IRA mole within the gardaí.

That was, he said "incitement to kill and that is what I have to live with."

The former detective sergeant was also asked about an incident when it was claimed he saved the life of an RUC officer. The two men were on their way to meet an IRA source in the Republic when Mr Corrigan said he saw known subversives in the area and what looked like an ambush.

He warned his RUC colleague and they sped from the scene.

He acknowledged that he did not file a report on the incident, nor did he track the vehicles involved or their occupants.

Mr Corrigan was also asked about the evidence from another former RUC officer who said he was told by the former detective sergeant to stay in Dundalk Garda Station for a while because republicans were downstairs in the public office.

Mr Robinson pointed out that on both occasions the RUC officers only had Mr Corrigan's word that what he said was true.

The kidnapping, torture and murder of John McAnulty by the IRA was raised during cross examination. It was put to Mr Corrigan that he was aware of the threats against people who passed information to the IRA and did nothing.

"You didn't care about sources. You didn't care about people subject to threats by PIRA. How do you reconcile that with your fight against subversives," asked Mr Robinson. "I think it sits very well," the witness replied. "I did as much as anyone could do."

Mr Corrigan had said he was aware of threats to a number of people, including Mr McAnulty, around this time but in answer to questions from Mr Robinson, he acknowledged that he did not file intelligence reports about the threats.

However, he said he thought he did his best at the time.

"That is a disgraceful position, utterly disgraceful. People were at risk and you ignored that risk," declared Mr Robinson.

He put it to the witness that his actions benefitted the IRA because people who were under threat were not warned, to which Mr Corrigan replied "that is speculation."

The Tribunal was set up to investigate suggestions of garda collusion with the IRA in the murder of two senior RUC officers in March 1989.

Chief Supt Harry Breen and Supt Bob Buchanan died in an ambush just minutes after leaving a meeting in Dundalk Garda Station.

Mr Corrigan was asked about what he did on the day of the killings. It emerged that just before 4pm there had been an attack just across the border.

The former detective sergeant said he was finished work at 4pm and he walked home.