Reporter Samantha Poling went undercover for Panorama: Crime Pays
In Panorama's programme Crime Pays, reporter Samantha Poling went undercover to reveal how major drug dealers and money launderers are making a mockery of high-profile laws designed to take the proceeds of their crime.
Here she talks about her investigation and how she won the confidence of one man whom she secretly filmed.
If I wanted to understand how organised criminals were managing to keep hold of assets - often to the tune of millions - I had to get close to them, earn their trust and hope they would tell me what I wanted to know.
This proved difficult, but doable, because many criminals harbour a deep sense of injustice at the way the state is trying to deprive them of their living, as well as their liberty.
And when that failed there was always the secret camera.
I learned of a man, Michael Voudouri, who had stolen millions in an international VAT fraud. Since he was jailed in 2004, the Crown has been fighting to take back the proceeds of his crime.
I was passed his number by a contact - a convicted counterfeiter who was helping Voudouri in his fight against the authorities.
They obviously seem to think I have the money somewhere. And after nine years of an investigation if you haven't found the money, when are you going to find it?
Voudouri was now out of prison and living in the affluent Stirlingshire town of Bridge of Allan, in a street known locally as Millionaire's Row. He agreed to meet me.
This was the first time he had spoken about his crime and the Crown's fight to get its hands on his money and his home:
"I got charged in 2000 and, because of all the legal stuff that was going on, eventually we got to court in 2004. It was affecting my family and in the end I thought, you know what, I'll just plead guilty and get it over and done with. It's now 2009 and I'm still not being left alone," he told me.
"They obviously seem to think I have the money somewhere. And after nine years of an investigation if you haven't found the money, when are you going to find it?"
Display of wealth
Standing in the grounds of his £2m home, Voudouri was quick to distance himself from the obvious wealth I found there.
He said the house is not his, that it belongs to his father-in-law. He added that the expensive Range Rover in the drive complete with personal number plate is on finance.
So where, I asked him, are the millions he stole? Money the state now wants back.
"I spent it," he said. "On having a good life."
Michael Voudouri says that he spent all of the money he stole
Voudouri has lodged appeal after appeal, most of it funded by legal aid. That means he has not yet handed over a penny. And his estimate is that the ongoing investigation will have cost the taxpayer as much as £10m.
"I went to prison for evading the tax of £3m. That's money that should have gone into the public purse, which I took. It's now cost the public though, since 2000 to date, £10m. So who's committing the crime now?" he said.
I knew that whilst Voudouri was a serious target for law enforcers, there were bigger criminals playing the system.
Graham Piper was convicted for his part in an £18m Colombian cocaine deal. He denied it but received the maximum sentence of 14 years.
The state is now after his wealth, but is struggling to prove it has not been earned legitimately.
After weeks of making calls to various contacts in the criminal world, I was eventually passed Piper's mobile number. He was now out of prison. After some negotiation, he agreed to meet me in a London pub.
Piper was clearly nervous, constantly looking over his shoulder. He told me I needed to earn his trust and that once I had, he would meet me again.
Graham Piper was secretly filmed for the programme
After weeks of speaking on the phone, we agreed a second meeting. This was my opportunity to capture on camera what I had suspected and what he had spent the last 10 years denying - that he had built his wealth on dirty money.
I headed back to the pub where we had first met. This time, I was wearing a secret camera.
Secretly filming criminals is always risky and filming Piper would be no exception.
This was a man deemed such a serious threat by the authorities that he had been kept in the maximum security jail Belmarsh. Segregated from the main prison population, he had been housed with terrorists. Whenever he went to court, there would be armed police and helicopter escorts.
During the meeting Piper admitted to serious crimes the authorities did not know about. And he told me he had put some of the dirty money he had made into his business:
"Some of the money I put back into the farm, you know, buying equipment. I hadn't disclosed that to them. I mean, I spent about 300,000 or £400,000 on building work at the farm. A lot of that was funded through cash money," he said.
Piper then admitted to something I was not expecting to hear:
"If you came to me with half a million quid and you said 'look, I've got half a million pound in English currency', that's a lot of money... so obviously if somebody wanted to go out of the country and take the money with them without being stopped and the money checked and questions asked, we would change the money up."
Here was the justification for our decision secretly to record Piper.
He had spent the last 10 years appealing the Crown's case for taking his assets, but here he was confessing to a probably multi-million pound money-laundering operation to a journalist in a London pub.
It will make frustrating viewing for the lawyers and investigators working on his case and for tax payers when they discover the sums receivers have made in his and similar cases.
He said he wanted to meet again, but when I checked the tape after he had left I knew that would not be necessary.
Panorama: Crime Pays, Monday 16 March at 8.30pm on BBC One.