Oxfam Scotland has led renewed calls for far-reaching reforms to make British and Scottish firms more transparent after new evidence they had been abused used for industrial-scale money-laundering.

As The Herald reported yesterday, four UK firms, two of them Scottish, were used as part of a £2.2bn Azerbaijani Laundromat uncovered by international investigative journalists.

The Sarajevo-based Organised Crime and Corruption Reporting Project found Glasgow-based Scottish Limited Partnerships (SLPs) were a core part of the structure. Money was then paid to politicians who acted in support of the former Soviet republic's autocratic regime.

The Herald yesterday also revealed that the Scottish office of a respectable accountancy firm, Saffery Champness, had hosted an SLP at the centre of a £40m Russian VAT fraud investigation that has already seen one man jailed.

Oxfam said a lack of corporate transparency lay at the heart of both stories. Its Scottish head, Jamie Livingstone, said: "These stories are a reminder of why it is so important for the UK Government to finally live up to the promise made by David Cameron in 2013 to put an end to tax avoidance through tougher transparency rules in the UK and our overseas territories.

"QCracking down on those who exploit weaknesses in tax and governance rules requires the complete closure of loopholes which enable wrongdoers to hide money and multinationals to avoid paying their fair share of tax."

With the commendable cross-party support of Scotland’s political leaders, Oxfam and The Herald helped secure a review of SLPs at UK level.

"While they are now required to publish more details about who owns them, these rules must now be closely scrutinised and imposed to ensure there is no misuse of the system.

"But beyond this, UK-linked tax havens such as the British Virgin Islands are still failing to publish registers of company ownership and thus still shelter corrupt money and untaxed profits. Through our work, Oxfam knows all too well that tax avoidance – often involving tax havens – robs developing countries of billions of dollars each year. "This is money which could pay for life-changing education and life-saving healthcare. "

Labour's Jackie Baillie added: "This investigation shows yet another instance of limited partnerships being used in immoral or illegal circumstances.

“Previously these structures have been used in billion pound bank scams in Moldova and now we see them used in a multi-billion pound money-laundering scheme in Azerbaijan.

“Scotland has a reputation around the world for financial propriety and we cannot allow that to be tarnished by becoming a magnet for money-laundering.

“The UK government must urgently tighten the regulations around these companies, and if necessary, abolish them altogether."

Tim Farron, the former Liberal Democrat leader, called for inquiry in to the Laundromat scandals, saying such things happened “when the corporate landscape is too lightly regulated."

Previously The Herald revealed that Scottish shell firms were used to move at least £4 billion out of the former Soviet Union as part of what is thought to be the world’s biggest and most elaborate money-laundering scheme. The Russian Laundromat was also uncovered by the OCCRP.