The Omagh bomb may have been constructed by a British double agent allowed to complete his work to protect his cover, it was claimed last night.
Amid growing furore over allegations the RUC was told of "Real IRA" plans to detonate a device two days before the August 1998 attack, new claims have emerged suggesting two previous explosions went off within hours of warnings that the same bomb maker was at work.
Speculation mounted that these were prepared by the same man and allowed to detonate as handlers sought to keep his true identity a secret.
A former agent, using the name Michael Clarke, indicated a failure to stop the bomb maker could point to a mole in "Real IRA".
"It makes perfect sense for the army or the intelligence services to allow the progress and delivery of a device of some nature to preserve and protect the safety of an agent," he told Channel 4 News.
"I believe that's possibly the case."
Security forces decided not to intervene in the mistaken belief the explosions would not pose a risk to life, it was reported.
One of the two other bombs at the centre of the fresh allegations went off in Banbridge, Co Down on August 1st, 1998, injuring 35 people.
It was said to have been of a similar size as the device used to kill 29 people in Omagh two weeks later, with same code word was used.
Clarke reportedly warned the British Ministry of Defence the bomb maker could be exposed.
"We were worried that if there was a possibility that he is an agent his life has been placed at risk," he said.
"His identity was going to be and is known, in which case it has placed him and his family at risk.
"I took appropriate action and informed the MoD of the relevant details and passed on the information to the senior, senior officer in army intelligence."
Neither the MoD nor the RUC was prepared to comment on the claims.
The fresh twist followed claims that the Northern Ireland Ombudsman has secured evidence alleging the RUC knew of plans to carry out a bombing 48 hours before the Omagh attack. PA