Thanks to my needing the loo in the department of government security, I've finally found out what's been happening to me; why my world has turned 16 shades of meatball since stumbling six days ago into the mad, bad and dangerous-to-know world of Bilderberg. My story is over. Here's how it ends ...

* * *

The meeting has been airless and fruitless. It has been the usual "How you know these are policemen?" and "Do you have the numbers of the motorbikes?" – the same old belittling of my word and my intelligence.

I explain again: "The detective at Omonioa police station told me that the two men following me, the two men I fought with in the metro station, were police officers. He said ...," and here I flip open my reporter's notebook, the one I found randomly in the street yesterday, my talisman, and read the quote: "'They are police. They are just doing their job, nothing else.' These men were the ones giving orders to the men in uniforms. And I was detained, even though I was the one who called the police. Can you tell me what is going on?"

"We have no information." I turn to the captain's colleague. Same face. "We know nothing about this incident." I've barely sat down and they "know nothing about this incident". I ask them directly: "How do you know that you know nothing?"

"We are the department that ... we look after the state, the government."

One of the men who arrested me in Vouliagmeni – nice to bump into him again in Athens. Photograph: Charlie Skelton/Guardian

"You protect politicians, government buildings?"

"Exactly. As a department we are interested mostly with anarchism and the people who do illegal actions. But of course, we don't know all the anarchist people ..."

So why have I been sent here? Why this department in particular? To the Ypodieftinsi Kratikis Asfalias – the department of government security? I ask them directly: what is my status here in Greece, what happens when they look up my name, am I a criminal? The deputy answers: "Only if you do a crime do you have a record. If you have not done a crime in Greece or in your home country you do not have a record. It is illegal to keep personal information on European citizens." That's comforting.

I ask again why I am being followed. I ask him if he thinks it's a problem that I've been so threatened by people following me around Athens that I took a cab to my own embassy. "No, I don't think you have a problem. They only follow you to see where you are going. I think they don't want to harm you. And if they do want to harm you, I'd sooner they don't do that in Athens." His words. Written in my notebook.

"They follow you from police station to police station. They know that you have informed police that you are threatened. They are more careful now." Glad he can see so clearly into the minds of the men (certainly not policemen, of course) who've been chasing me around.

I show him the photo I took of the man I grappled with in the metro station. The one whose partner shoved me about and forgot that he wasn't a police officer, pointing into the little metro police office, screaming at me "Get in here! Get in here!" and marching in ahead of the uniformed officers. In charge. I ask the captain if he recognises the man. "No."

I show him another photograph, of a man I saw coming out of this building, yesterday, when I came to arrange an appointment. He was one of the pair who arrested me the second time in Vouliagmeni, for taking photographs of car wheels. We recognised each other and laughed as we passed. I took his photograph. I showed the photograph to the officers. Bless them, they couldn't help but smile. Hands wiped across mouths to become stern. Glad they're taking this in such good spirits. "So you recognise him?" Serious faces now. "He reminds me of someone I know, but ... no ... I don't know him." They're quoting me lines from bad movies.

It's going nowhere. I get the address of another police department, get the captain's name, and ask his advice. I could use it. "Here in Greece we have a saying, we hold a small basket to anything we hear and to anything we see. I do not have big expectations for your situation."

The interview is over, I've been successfully stonewalled, nothing confirmed, nothing certain. The cloak of Bilderbergian darkness still envelops me. I'm going to go to the Acropolis and scratch rude words in a pillar or something. Anarchist that I am. But first, I need the loo. And at this point, the captain makes his big mistake. He lets me go. And everything changes.

I am led along the sixth-floor corridor to the lavatory. And there, standing there – bam – right in front of my eyes, is one of the men who's been following me around Athens. The one who tailed me here on the first day. The one who I gave the slip to in my stairwell, and then quietly watched as he stood at the edge of the museum park, scouring the tourists. He was looking anxious. I waved cheerily when he finally spotted me. It was him. It was proof. Everything up until now could be fudged, denied, explained away, attributed to coincidence or paranoia, but not this.

I think he was as shocked to see me as I was to see him. He didn't know what to do, so he literally ran off. He ran away, into his office. I darted after him – what was I doing? I was yelling, I was pointing: "Here! One of the men! One of the men who's following me!" I whistled to the captain up the hall: "In here, he went in here!"

It was absolute, unbridled mayhem. Detectives came into the hall, people were shouting, I was led back up the hall. I was FUMING. I was shaking. I was angrier than I've ever been in my life. All I've been, all along, is lied to. Harassed and lied to. And I only caught them out because of an extra cup of coffee at breakfast.

The captain was in a tizz. "Wait here, we sort this all out now." Mutterings from next door. A minute later and I'm ushered into the boss's room. The chairs were plumper, the TV screen showing Eurovision highlights was bigger, and he was fatter. "Sit down." I sat.

"What's your problem?"

"I think you know what my problem is."

"There is no problem."

"I saw a man, up the hall, in the lavatory. One of the men who has been following me."

He looks me deep in the eye, not a blink.

"There was no man. You did not see any man."

My mouth actually fell open. I looked at him open-mouthed. There were no words. Again, it was just "an idea in my mind". I had imagined it all. I'd encountered a phantom taking a leak.

"Close your mouth. It is rude to sit like that with mouth open."

I wasn't blinking either as I said: "It's rude to lie."

"There was no man."

"Shall we go and ask him? He is just up the corridor."

"You go now."

"And that's the best you can do?" I looked around at the captain; at his colleague. "This is crazy."

"To you it is crazy. Not to me." He started punching numbers into his phone, it was over. "I have a job."

"I have a job, too."

But you know, it didn't matter what he said. I have been stalked and harassed by Greek government security, I have hidden from them in stairwells, challenged them in the street, tried to arrest them, and been lied to by them. The Greek prime minister, Kostas Karamanlis, was a delegate at Bilderberg 2009, and the special government security department of his police force has been protecting him from me. Protecting the dignitaries from a sort of journalist. A dangerous man. I wonder how much it all cost. How many thousand euro. I bet Greek taxpayers would love to know.

I haven't had time to reflect yet. This is me writing off the top of my head in a nice populous cafe attached to my hotel. Lots of people around. I'm too tired and baffled to think any more. I may not know a whole lot more about what went on at this year's Bilderberg, but I know what went on up the road, and further still, in Athens' city centre. I came to make a few cracks about Bilderberg and ended up getting sledgehammered in the nuts.

I tell you one thing: they're not very good at their job (unless their job was to freak me out). If I was the Greek prime minister I'd be out looking for better spooks. How about Avion? We know they were at Bilderberg, why not extend their contract ...?

Right now, all I want to do is to go home. I'm sitting here scared to go to the loo. I don't like the look of the stairs. I'm thinking of giving the bellboy €20 to stand outside while I pee. When I filled out my report in Sintagma police station, with the nice captain, he was obviously using the wrong paperwork because there was a box where it said: "Name of item lost." It was a lost property form. I wrote "innocence".