A former agent at the centre of the Omagh investigation controversy is thought to be prepared to hand over recordings of conversations with his security force handlers to defend his credibility.
The man, who is known as Kevin Fulton, has claimed that he has tapes of up to 27 secretly recorded conversations with some of his MI5, RUC Special Branch and British army handlers which he has reportedly threatened to pass on to the Police Ombudsman, Ms Nuala O'Loan.
Three days prior to the Omagh bombing, Mr Fulton told his RUC handlers of his suspicions that dissident republicans were preparing a massive bomb. In her report, Ms O'Loan said Mr Fulton's information had "not been given sufficient weight" and had "not adequately been followed up", although she concluded: "Even if reasonable action had been taken . . . it is unlikely that the Omagh bomb could have been prevented".
In his reply to the Ombudsman's report, the Chief Constable, Sir Ronnie Flanagan, said significant parts of Mr Fulton's information were "either erroneous or implausible" and none of it had related to Omagh. In his initial rebuttal of Ms O'Loan's findings he described Mr Fulton as a "Walter Mitty-type character".
On one of the tapes, reportedly obtained by the Belfast-based Irish News, a named Customs and Excise officer appears to warn Mr Fulton that he could potentially be exposed by other security agencies to protect informers in more prominent positions in republican paramilitary organisations. Customs and Excise has refused to deny whether Mr Fulton had ever been an agent for them.
Mr Fulton is also believed to have hand-delivered a letter to 10 Downing Street several weeks ago on behalf of a group of former agents who feel they have been "disowned" and "abandoned" by the British authorities. In the letter, the group, calling itself "Mole", reportedly referred to the killing of the former intelligence agent, Mr William Stobie, and urged the British Prime Minister, Mr Tony Blair, to meet them to assuage their fears. Downing Street sources have confirmed the authenticity of the letter but said the request for the meeting had been refused. Mr Fulton is understood to have acted as an agent for the security forces for 20 years.