Nearly two years ago a law enforcement source flagged up a lengthy document to The Herald. It was a report from a firm of forensic accountants hired by the parliament of Moldova, Europe's poorest nation and the smallest of the 15 former Soviet republics.

Experts had been asked to find out what had happened to a billion dollars that had disappeared from three of the country's banks. They found the money, in theory at least. It was owed to an obscure Scottish legal entity registered at a former local authority home in Pilton, Edinburgh. The BBC, which also had the story, called this the "billion-dollar ex-council flat".

The entity was a Scottish limited partnership, a unique kind of business whose owners can be anonymous, pay no taxes and file no accounts but can, just like a real company, own assets.  It was one of a score - as well as other British and foreign companies - used to carry out what was essentially one of the world's biggest bank heists.

Over the last 18 months or so The Herald has exposed hundreds of such SLPs being abused by international criminals and others for a whole variety of uses. We have found SLPs being used to front for unethical online businesses flogging diet pills that do not work or combs that promise to make bald men's hair grow back. But the structures - particularly popular among internet criminals from the former Soviet Union - are also used to hide the true owners of very dangerous online business, such as peer-to-peer sites used for everything for sharing child abuse images to bootlegged Disney films and Israeli-based binary options betting scams, described by British police as the biggest online scam of our times.

We have also exposed the repeated abuse of anonymously owned SLPs by corrupt officials in the ex-USSR, including for the "skimming" of millions from controversial arms exports. Last week we revealed more than 100 SLPs - alongside other types of firms - were used as part of the legendary Russian Laundromat, the biggest and most elaborate money-laundering scheme ever exposed. At least £16bn was stolen from Russia.

The UK Government earlier this year announced a review of SLPs after what its security minister, Ben Wallace, described as "very concerning" stories in The Herald. Mr Wallace was responding to evidence from The Herald to a committee in the House of Commons on the use of such companies as part of a "money-laundering kit" marketed online alongside anonymous bank accounts from the Baltic States.

However, not all SLPs are criminal. Scottish law firms over the last decade have repurposed the structure from an obscure entity used for farming tenancies to what they regard as a useful tool for international equity funds.

The Law Society of Scotland yesterday came out against any radical reform of the structure, instead suggesting wider regulatory improvements. "Partnerships and limited partnerships are commonly used business structures as they offer operational flexibility and tax transparency," said its director law reform, Michael Clancy.

The Law Society is not denying that SLPs are abused. They are questioning whether they are abused more than any other corporate structure.

Analyst Richard Smith has crunched figures for SLPs. Their number has grown far faster than for other kinds of structures.

Last year 300 SLPs were set up for transparent financial purposes, such as the Formula One acquisition. However, there were 4884 anonymous ones.

So the controversial business Mr Clancy and the Law Society is trying to defend is simply dwarfed by a massive grey economy of opaque structures, scores of which have been exposed as fronts global gangsterism by this newspaper.

SLP Registrations

HeraldScotland:

Source: Companies House data analysised by Richard Smith