What does the theft of a billion dollars from Europe's poorest country have to do with a run-down housing estate in Edinburgh? Moldova was robbed of 12% of its GDP by the bafflingly complex financial scam uncovered earlier this year. It involved a web of companies in the ex-Soviet country, with the money thought to have ended up in Russia via Latvian banks.

But the trail also goes via a number of UK-registered companies, including one based in the district of north Edinburgh made famous by "Trainspotting", the novel about heroin addicts. It's not the only example of Eastern European fraudsters using the UK to launder their dirty money in this way. So why is it allowed to happen? Why is it so easy to set up an opaque shell company in the UK? And what is the role of so-called company formation agents? Tim Whewell investigates

Reporter: Tim Whewell Producer: Simon Maybin.