The Real IRA has claimed that Kieran Doherty, whom it abducted and murdered last week, had admitted his involvement in a €500,000 cannabis factory uncovered by gardai in Donegal last month.

In a statement, a representative of its ‘Army Council’ claimed Doherty (31) had made the admission during a six-week ‘investigation’ by the Real IRA following the discovery of the drugs factory.

Doherty’s family have strongly denied he was involved in the drugs trade.

The dissident spokesman said Doherty, who was a prominent member in Derry, had been “interviewed” twice by the Real IRA before the night of his murder.

The Real IRA said that at the second interview, at which Doherty was “court-martialed”, he had made the admission after hearing “witness statements” from other members of the criminal gang who were allegedly involved with him in the cannabis factory.

The Real IRA spokesman said that Doherty had been a member of its “GHQ (general headquarters) staff” and had known the organisation’s rules when he joined.

While Doherty had admitted involvement with the drugs gang, he had denied working for MI5, the spokesman claimed.

However, the Real IRA believed that MI5 “had played some role” in the drugs factory which had been set up to “blacken the IRA’s name and link us to the drugs trade which we abhor and oppose”. The cannabis factory was discovered by gardai at a house in Carrigans which was owned by Seamus McGreevy (56) from Co Meath, a founder Real IRA member who killed himself over a month ago.

McGreevy had built the house but had been unable to sell it due to the property market slump. He asked Doherty to rent the house to tenants and to act as its caretaker. The two men, who met when they were serving sentences in Portlaoise prison, were described as being “like father and son”.

The Real IRA said that, from its investigation, it believed McGreevy had no involvement in the cannabis factory and was horrified when it was found. “After the drugs factory was uncovered, the IRA stood down its entire Derry brigade pending the outcome of our investigation,” the spokesman said.

“An outside IRA security team moved in to carry out the inquiry. It was an extensive investigation during which many witnesses, including members of the criminal gang involved in the drugs factory, were interviewed.

“Those individuals gave statements saying Kieran had been integrally involved in setting up the whole operation and had actually sourced the cannabis plants.”

The spokesman claimed when Doherty was first interviewed at a paramilitary “court of inquiry”, he denied these allegations. However, the Real IRA representative claimed that on the second occasion when Doherty faced a “court martial” and was shown statements from the gang members, he “admitted his involvement”.

The spokesman said that at both “interviews” Doherty had been ordered not to discuss the issue with anybody nor to contact other Real IRA members.

“However, on Bloody Sunday (January 31), Kieran phoned Seamus McGreevy who was having lunch at his sister’s home. Whatever Kieran said led to Seamus leaving, returning to his own home, and then hanging himself,” added the spokesman.

McGreevy came into a very substantial sum of money when a motorway was built through farmland he owned. Republican sources said he gave most of this to the Real IRA and also to ex-prisoners who were struggling financially. They said he had given Doherty money to set up a café for himself but the venture had failed. Republican sources described McGreevy as a “very trusting, quiet countryman”.

Until the discovery of the drugs factory, Doherty had been a popular member of the Real IRA nicknamed ‘Harry Potter’ or ‘Goggles’ because of his glasses. The Real IRA claimed it had “strictly followed the green book”, the IRA’s rulebook which all members endorse, during its ‘investigation’ into Doherty.

The spokesman claimed that admitting one of its members had become involved in the drugs’ trade, and then killing him, was “not something we did lightly”.