The founder of the Real IRA was formally released from prison on Easter Sunday after serving 13 years of a 20-year sentence for directing terrorism.

Michael McKevitt, 65, spent the past number of weeks on temporary release at his home in Blackrock, Co. Louth. He was formally released after his sentence expired on Sunday.

McKevitt, who has cancer, was one of four men found liable for the Omagh bombing in a civil action at Belfast High Court taken by relatives of the dead. The Real IRA bomb killed 29 people and unborn twins on August 15, 1998.

McKevitt denied having anything to do the atrocity. He claimed he “was stitched-up from the outset.”

On his prison release McKevitt launched a stinging attack on his former Sinn Fein colleagues and questioned the party's claim to be republican.

He said in a statement, “When I look at Sinn Fein, I believe their behavior is akin to that of the looters on the streets of Dublin in 1916.

“They have turned the centenary commemoration into a financial racket, exploiting it for all they can. Shameful is probably the best description that I can use.”

McKevitt refused to state that dissident republican paramilitaries should end their campaign of violence in the North.

“It is immaterial as to whether I agree or disagree -- armed struggle or guerrilla warfare is a tactic which has been around for hundreds of years,” he said.

“Historically, the only form of resistance in Ireland that the British actually took notice of was armed struggle like they did in 1916 and in every decade since.”

As quarter-master general of the IRA, McKevitt broke away from the Provisionals to form the Real IRA in 1997 and became a high-profile opponent of the Adams-McGuinness leadership.