What was the undercover officer doing in New York in 2008? He claims to have worked for the FBI ? did you encounter him?

Was Mark Kennedy, the infamous police spy who infiltrated political activists in Europe, also an FBI agent? And can you help us work out what he was doing in New York?

In an interview with Rolling Stone magazine, Kennedy, who spent seven years living as green campaigner 'Mark Stone', claims to have received a special commendation from the United States federal intelligence agency. The FBI declined to comment on the story, but Kennedy provided some tantalising details to the US magazine.

In 2008, with the approval of the US government, Kennedy traveled to New York to spy on a secret meeting of European and American anti-capitalists, including members of the Earth Liberation Front and student activists from Stanford University, who were planning to disrupt the upcoming Republican and Democratic conventions.

Posing as Stone, Kennedy shared his logistical expertise with the assembled activists, not far from where the Occupy movement would later take off. Based on what he saw in New York, though, he did not know what all the fuss was about. "It was a bit of a pointless meeting," he says. He told his superiors that the group, who struck him as young and naive, didn't seem like much of a threat. A French activist suspected of advocating armed revolution was followed as a result of his spying, but no arrests were made.

If you are a US-based activist ? were you at this so-called 'secret meeting'? Do you recall meeting Kennedy? Or does anyone stateside know how we might find out more about his time there?

Kennedy has a good record of lying and we have been careful in the past to take all of his public prouncements with a pinch of salt. The article, which you read in full here (warning: paywall), he also offers his thoughts on the failings of the Occupy movement, which he reckons is being infiltrated on a "day to day basis", is one of Kennedy's typically one-sided proncouncements.

But the French connection is an intriguing one. An article published in the French magazine Les Inrockuptibles this week alleges intelligence gleaned by Kennedy was passed to the French intelligence services, and proved significant in bringing about the 2008 arrests of the Tarnac Nine. (We wrote about the Tarnac arrests here.)

The article by journalist Camille Polloni also refers to a group of campaigners in New York ? saying it took place in January 2008. The piece refers to Kennedy attending an impromptu get together of friends (rather than any clandestine rendezvous) with an anarchist associate from England.

We now know that Kennedy turned into something of an agent for hire, infiltrating at least 11 other countries. Recently he admitted to playing an important role in Denmark, while his deployments in Germany, Ireland and Iceland have prompted angry responses from campaigners and parliamentarians.

Previously, nothing was known about his FBI-deployment in the United States. Can you help us find out more?

Email paul.lewis@guardian.co.uk or rob.evans@guardian.co.uk