"This is the Federal Security Service of the Russian Federation. Do as I say. This is an anti-terrorist operation."

It was only then it hit me: I was being interrogated. These were serious people and they set to work professionally, in a style that was almost courteous. My interrogator was never rough and never raised his voice, at least to me. But I will always remember his face — long, with a drooping lower lip and a desk-bound pallor. "Open your bags. Take out all your books, your credit cards and all the business cards given to you. Open your computer. Let me copy everything on it." 

My interrogator was from the North Caucasus, working for the federal FSB, the security police, not the local branch. He was a quality cadre: English-speaking and keen to tell me he had travelled frequently to Holland. Three or more armed underlings came in — rough, tough men with six o'clock shadows, rifles and a Kalashnikov. One was in police uniform, the second in a military outfit and a third had FSB insignia on his vest. They laughed and sneered as they began to work, picking through my books and clothes. "Why are you writing anti-Putin material? Why are you asking questions about Putin? Are you a fool not to realise — Putin saved us. Putin saved Russia from collapse?" 

The interrogator laughed, fiddling with a cigarette scavenged from a colleague. He put it unlit in his mouth. You could feel how suffocating boredom must be for these men. The outpost felt as if it had been waiting a long time for a "spy", that it had almost given up on catching anyone but Tajik heroin traffickers and Tuvan hashish dealers. The computer screen displayed an advanced session of "Bejewelled", a free online MSN stacking game. 

The man in charge stayed civil and gave me a few smiles, even an apology. Then he found Tuvan opposition newspapers in my suitcase. His face darkened. A piece of paper was placed next to the handcuffs and I was told I would have to write a "confession". They began photocopying every notebook, then my bank cards, before downloading every file on my computer. It was only then, as I saw the FSB man flicking through interviews with Alexey Navalny, the opposition leader, that I realised what potential danger I was in. Suppressed fears surfaced. 

I was denied the right to call the embassy. The questioning continued. Did I work for MI6? How was he supposed to know I didn't work for MI6? Wasn't this exactly what MI6 would be doing — investigating how stable Russia was at its edges? After about an hour we returned to the people carrier. I was instructed to pick two witnesses for my written confession, "to see that we did not beat this man, break this man, break any laws of the Russian Federation or dictate to him what he will now be signing on his activities".