One of the high, single-paned front windows at 78 Montgomery Street is broken. A magazine has been taped across the crack, obscuring the view of a small, overgrown garden where an old disused telephone box lies on its side.

This is Edinburgh, one of the Scottish capital’s oh-so-respectable neighbourhoods of stout Victorian tenements. The address, smashed glass aside, could not seem more legitimate. In reality, it could not be more criminal.

That is because number 78, on paper at least, is one of Europe’s great money-laundering hubs, a centre of elaborate multi-billion-dollar schemes to clean some of the continent’s dirtiest money.

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The property’s owner, John Hein, finds this characterisation of his home to be “preposterous”. But after years of almost constant police visits over one investigation or another, Mr Hein now acknowledges he lives at one of Britain’s most crooked addresses. “It's horrifying,” the 60-year-old admits stressing he has nothing to do with money-laundering, gangsterism or their profits. “My lifestyle it is not one of a multi-million-pound criminal.”

There is no cash at Mr Hein's home, which, he admits, is "modest". Instead there are, officially at least, thousands of anonymous shell companies, mostly Scottish limited partnerships or SLPs.

They don't have so much as a brass plate to their name. But they have been used, on an industrial scale, to move money out of the old Soviet Union.

SLPs, once obscure structures used by Scottish farmers to share with friends, are dubbed “Britain’s home-grown secrecy vehicle” by anti-corruption campaigners Transparency International.

Why? Because their real owners to remain anonymous, pay no taxes and file no accounts. SLPs can even own assets like ships, farms or hotels, often concealing their true controllers.

Over the last decade they have been openly marketed around the world as part of what amounts an off-the-peg money-laundering kit. For perhaps £1500 anyone wanting to own assets or move money anonymously could buy themselves an SLP with parent firms in tax havens and a bank account in Latvia or Cyprus.

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Cue mass exploitation by global criminality, and nowhere more so than at 78 Montgomery Street.

SLPs at the address have been played key roles in four successive giant money-laundering schemes. Their bank accounts were used to help clean money in the sophisticated multi-billion-dollar Russian and Azerbaijani Laundromats exposed by the Organised Crime and Corruption Reporting Project (OCCRP), and $1bn looting of three banks in Moldova revealed in 2015. Some 50 SLPs based at Mr Hein's home were named in the Russian Laundromat. In total some $4 billion was funnelled through Scottish entities, including those in Montgomery Street, according to OCCRP raw data analysed by The Herald.

Then, this weekend, firms based at the home figured in bank and court documents obtained by Al Jazeera Investigations relating to $1.5bn worth of assets seized from the circle of ousted Ukrainian President Viktor Yanukovych.

An analysis of raw paperwork from Al Jazeera by the Sunday Herald found seven SLPs and three limited liability partnerships, another corporate entity frequently used as a shell firm, had paid around $50m in to the accounts of two firms named in court orders as money-laundering vehicles for what Ukrainian media calls the Yanukovych "family", the group of associates who profited under his rule.

Three of those SLPs - Millteks Management, Spanxter Sales and Armenpak Sales - were registered at Mr Hein's house. Spanxter alone paid around $17.5m for building supplies to a firm in Belize named in Ukrainian court documents as a front for the Yanukovych family.

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There were no supplies delivered to Mr Hein's home. Nor is there any trace of any construction work or any real economy activity by Spanxter or any of the other roughly 3000 shell firms that share his address.

Mr Hein had no idea, he says, what the businesses were being used for. A company formation agent, he had been asked by an English-based colleague to host Scottish entities. All he had to do was provide an address and post on any mail. Eventually he provided this service to as number of agencies, who negotiated bulk deals.

Then the knocks came at the door. Because 78 Montgomery Street's SLPs were starting to get noticed by the law, especially outside Scotland. "We obviously know the local police really well," Mr Hein said. "They come along and take a statement, usually on behalf of a foreign police force. At one stage they were there every two or three weeks." Statements, Mr Hein said, were reduced to a pro-forma. He confirmed such and such a firm was registered at his address but that he knew nothing about its activities. "We were not in a position to establish the bonafides of the ultimate client from different parts of the world. We were relying on the formation agents who had their own checks."

The first big story was Moldova. Three banks had been emptied of $1 billion by Ilan Shor, a baby-faced 20-something millionaire married to a Russian pop star feted by Vladimir Putin. Last summer Mr Shor sentenced to seven and a half years in jail - but is free waiting an appeal.

"I thought 'My Goodness'," said Mr Hein, remembering how the police told him of the scale of the crime. "They were talking about the large proportion of the GDP of a small country had gone through our address."

The three Moldovan banks were robbed by a series of complex but ultimately unreturned loans, often involving British and Scottish firms. The network of corporations used in the robbery, shell firms nestled one inside the other like Russian Matroyshka dolls, was first exposed in full by a US firm of investigators called Kroll. Among other entities used, it named an SLP registered at 78 Montgomery Street called Avenilla Commercial.

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This firm, finally dissolved in November 2017, was first created by a company formation agency called Administrative Providers Limited which is registered in Milton Keynes, England, but controlled by an individual in Latvia. The same agency made the three Montgomery Street SLPs in the most recent Ukrainian scandal, including Spanxter Sales. It also created an SLP called Querto Services first exposed by The Herald for fronting for a whole series of websites offering a range of bizarre products, including a £512 electric comb it says will help correct male baldness, a body-building supplement that it claims will make customers “look 52 per cent more ripped” and female raspberry ketone diet pills dismissed by doctors as useless.

Mr Hein said: "We had one or two obvious consumer frauds. One was selling worthless anti-flea discs for pets. We were sent loads of them from somebody who was furious and wanted their money back.

The Herald later found Querto was providing payment services to websites in the multibillion global binary options investment fraud. There is no suggestion that Administrative Providers Limited, which created around 250 SLPs and has another 250 English LLPs at its Milton Keynes address, has any knowledge of what any of its client businesses do.

Mr Hein, who had a stroke last year, is finding all the scandals tough.

"If I got any money for it, it would be slightly more tolerable. But I am not getting a penny." The former Liberal Party parliamentary candidate has withdrawn from the SLP hosting business. But that does not mean he can get rid of the partnerships.

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He just has to wait for the next scandal, the next knock on the door from the police. Companies House, Britain's corporate registry, sometimes takes over the address of a limited company. It does not do the same for SLPs. A few have been transferred by their secret owners to one of Scotland's other hives of shell firms, high street virtual offices or provincial council houses. Most just stay registered behind the cracked panes of 78 Montgomery Street.