DENIS Sugrue's Ireland-bound flight was sitting on the tarmac of the Los Angeles International Airport when four armed FBI agents burst on, waved an arrest warrant in his face and led him away in handcuffs.

His offence was being a Russian agent – or "spymaster" as Time magazine would later call him. He just didn't know it yet.

He didn't know he was being carefully monitored by counterintelligence agents who had been following him in cars and staking out the airport, or that he was about to be detained in US custody for 15 weeks.

Five years after his arrest sparked headlines across the world, the Irish businessman has published a memoir on the incident that changed his life and, despite never having been charged with any offence, he says the US government still believes they got the right man.

"They still think that I'm a spy," he told the Sunday Tribune from Russia, where he is based with his family and from where he runs his technology company Amideon.

When news reached Ireland that Sugrue (58) had been arrested for "attempting to export defence articles without required licence", according to the official intelligence file, it was difficult for anyone to believe that a Galway businessman could be a spy.

"I was in LA in January 2005 sitting in the aircraft and four FBI guys called me out and I was put into handcuffs and they waved an arrest warrant in front of me and they put me in prison," he said. "There were never any charges."

His subsequent experience unfolded like a film script, carefully written to a plot that had everything from an innocent political stooge to government agents, undercover stings, clandestine car pursuits, a spell in prison and a conspiracy that went straight to the White House.

Sugrue, as he admits himself, fitted the profile: a travelling businessman dealing in high-end technology with resident addresses in Ireland, Moscow and Kyrgyzstan.

He was targeted for purchasing an 'equalizer/demodulator' in the US for shipping to Russia via Limerick, but, as he tells it, this was simply standard broadcasting equipment designed and sold with official consent.

"We had a deal with an American company to co-design a product for the [equivalent of] the Federal Communications Commission [FCC] in Russia who allocate TV frequencies as the FCC does in America," he explained. His licence to trade would prove the FBI's undoing.

In the meantime, though, Sugrue was cast in a world of espionage and 'spymasters' by some of America's most high-profile media outlets.

"I was thrown in prison and the case began to unravel because the thing that we were buying was legal to buy and we had all the supporting documents," he said.

"But for some reason Time magazine ran an article which was called 'The Russians Are Coming' and it said I was part of a Russian spy ring in America. Newsweek said later that the FBI called it a major breakthrough in curbing Russian espionage."

Although remarkably calm about his experience, Sugrue believes the operation was at least partly motivated by the political establishment and climate of the day.

While a suspicion at best, he says there was pressure on President Bush to be seen to tackle the perception that Russia was "flooding" the US with spies – a conspiracy theory that would come to life comically last June with the arrest of 10 'sleeper' agents scattered indiscriminately through US suburbia.

"I was detained for 15 weeks. It was a combination of prison [the Metropolitan Detention Centre in Los Angeles] and I was electronically tagged all the time. Then I was on a 30-metre electronic chain so I couldn't move. That was outside [prison] in the house of a friend of mine," he said.

"There were three interrogators. At the beginning they were as confused as I was as to what it was driven by – something between the Russian president Vladamir Putin and Bush. This guy in the FBI intelligence needed a Russian spy and he decided it was me. He had one.

"They needed something for a meeting on the 22 February. Bush was under pressure at the time to be tough on the Russians. That was the theme of what was going on at the time.

"I think they genuinely thought that they had a spy – a guy spending 15 years in Russia and doing business in Russia. They were looking for someone."

Eventually, when Sugrue bizarrely agreed to admit to a "mislabelling" offence – a minor rules infringement but not a crime – and pay $20,000 in compensation he was allowed to go. This, he says, was a face-saving exercise for the authorities who had clearly got the wrong guy.

"The case was obviously beginning to disintegrate because the Department of Commerce had said the materials in question were legal," he said.

Sugrue spent the last number of years writing down his memories of the affair in his newly published book The Russians Are Coming. Legal actions against both the US government and Time were possible but ultimately unlikely to yield success and so for now the story is over. At least it is for him. "They were sure they had a spy and that spy was just too clever. When I finished the book and got an editor, I went back to all of the people who were named in it," he said.

"I sent a copy to the FBI for review and seven days later they sent two FBI agents to the house of a friend in the US with a message that they were watching me.

"I know this sounds incredible but this actually happened. Two weeks later they contacted another friend of mine and asked him to spy on me."

Sugrue hasn't returned to the US in five years but still continues to trade with his American business associates. He is free to come and go as he pleases but America will never seem as hospitable is it may once have been.

"I believe they are still watching me," he said in his nonchalant style. "That is what they said so I have to believe them. But they can if they want to."

www.therussiansarecoming.net