An FBI spy who infiltrated the Real IRA was involved in picking up runaway teenage girls to sleep with and “keep like puppy dogs”, the Omagh bomb civil action has heard.

Lawyers for jailed terror chief Michael McKevitt likened David Rupert to an iceberg, with nearly all of his treachery unexposed beneath the surface.

Rupert was a con-man prepared to do anything short of murder, and anyone who tangled with him came off badly, it was claimed.

Michael O’Higgins SC delivered a withering critique of the American trucking boss-turned-undercover agent during his closing submissions at the multi-million pound compensation trial in Belfast.

McKevitt, who is serving a 20-year-sentence for directing terrorism, Liam Campbell, Seamus McKenna, Colm Murphy and Seamus Daly are being sued by relatives of some of the 29 people killed in the August 1998 Real IRA attack on Omagh. All five men deny liability.

Mr O’Higgins also accused Rupert’s intelligence service handlers of directing Rupert to perjure himself when he appeared as a star prosecution witness at McKevitt’s criminal trial in Dublin in 2003.

“That is a serious and shocking allegation I have made against a government agency,” the barrister acknowledged.

“It would not just be irresponsible but an abuse of Counsel’s position if there was not some material to support it.”

He pointed to alleged attempts by a senior MI5 operative to get a Garda Chief Superintendent to tell lies to back his argument.

Mr O’Higgins questioned what impact the alleged perjury plot would have on Rupert, who he described as being “as dishonest as the day is long”.

He added: “I’m thinking more days in northern Norway in June than December 21 in somewhere like here.”

During a detailed exploration of Rupert’s character, the court was told how he “recalibrated” after being raised in a household with a strong Protestant ethic.

Describing Rupert’s outlook on business dealings, Mr O’Higgins said: “Short of murder you could take them to the cleaners for as much and as often as you liked and you could sleep well in your bed.”

He went through decades of |incidents, including an alleged money laundering scam involving a Mafia lieutenant from New York, and times when Rupert was |declared bankrupt.

After one of these occasions he went to live in Florida for a year, driving a Porsche car which he claimed was being “held together by dirt”, the court heard.

Casting doubt on the spy’s |account, Mr O’Higgins suggested another possible scenario was that he was living it up on money he spirited away from creditors.

He then set out an incident |about which Rupert was questioned when underage girls were allegedly taken across state lines.

The barrister said the businessman at first claimed he was just picking up hitch-hikers, before blaming his fellow driver for sleeping with a girl aged 15 and wanting to take her home after the trip to “treat like a puppy dog”.

But Mr O’Higgins continued: “There were in fact two people in the truck.

“That is a reprehensible thing to have done. For truckers to be carrying 15-year-old girls to sleep with and to keep like puppy dogs, from one side of the United States to another, is in my submission reprehensible to the highest |degree.”

In his submissions he claimed Rupert “spent every waking hour of every day with his eye on the main chance” of taking money from people. He described the series of incidents listed to the court as being the tip of the iceberg.

The hearing continues today.