The corrupt circle of an ousted Ukrainian president profited from last year's Eurovision thanks to a British shell firm.

A major BBC investigation has found the Kiev venue used to host the show's after-party was owned by an entirely opaque firm registered in England's Home Counties.

Their probe comes amid a growing chorus of concern about the abuse Scottish and English shell firms, not least as a way for criminals and corrupt officials from the former Soviet Union to make or hide dirty money.

The Eurovision firm shares an address in Potters Bar, just outside London's M25 ring road, with more than 100 other firms used to launder at least £1.2 billion.

That figure was calculated by Herald contributor Richard Smith using raw data from Organized Crime and Corruption Reporting Project.

BBC Radio Four's File on Four programme, broadcast on Tuesday, discovered that one firm at the address owned the Parkovy conference centre in central Kiev. It said the ultimate owner of that firm was somebody in the circle of Viktor Yanukovych. That means his cohorts - believed to have stolen nearly £30 billion from Ukraine - are still profiting four years after his ouster.

Transparency International, the anti-corruption group, has been urging reforms of Britain's corporate regime to stop shell firm abuse.

Its Rachel Davies Teka said: “UK companies are being created purely as get-away vehicles for corrupt individuals stealing money from some of the poorest populations in the world.

"We have to ask who is setting up these companies and why the system allows many of them to do so with little to no oversight.”

“Let’s be clear, some of the biggest cases of corruption around the world are made possible with the complicity of British based companies and the professionals that help form them.

"This is a national disgrace and whilst efforts have been made to end this problem, a lack of proper oversight and resourcing means we are still some way from ending our complicity in global corruption."

The UK Government signalled to The Herald this week that it would announce reforms "soon". We have previously revealed the mass avoidance of transparency rules introduced for Scottish limited partnerships last year. That was an extension of a regime introduced for other companies in 2016 under which most corporate entities ave to name a "person of significant control" or PSC, if they have one.

File on Four revealed new research from another anti-corruption group, Global Witness, in to compliance with the PSC regime. They found that nearly one in 10 UK companies - 350,000 - still had not named one.

There can be reasons not to file. But Murray Worthy, senior campaigner at Global Witness, said the number was "worryingly large".