Russian and Swiss law officers began talks yesterday on Swiss allegations that an Isle of Man branch of the then Midland Bank was used to pass $25 million in bribes to the man who helped President Vladimir Putin to power.
The Swiss federal prosecutor, Mr Valentin Roschacher, pressed his Russian counterpart, Mr Vladimir Ustinov, to speed up the inquiry.
A Swiss document given to the Russians in July and leaked to newspapers in Italy and Russia this week alleged that Mr Pavel Borodin, the former Kremlin property manager who Mr Putin says recruited him into the Kremlin in 1996, received more than $25 million for awarding contracts to refurbish the Kremlin and other government offices.
In all, $62.5 million was paid in bribes for contracts worth $492 million, it is alleged. Mr Borodin's share was paid into the Midland (now the HSBC) account on the Isle of Man of Lightstar Low Voltage Systems Ltd, the Swiss document says.
Mr Borodin, his daughter Ms Yekaterina Siletsky and son-in-law, Mr Andrei Siletsky, had the money - $25,609,978 - transferred to their accounts in Geneva, Nassau and Guernsey in four payments between March 1997 and August 1998, according to the document by a Swiss investigating magistrate, Mr Daniel Devaud.
"The elements collated to date show that [Mr Borodin and 13 others] may be seriously suspected of using the Swiss banking system to conceal money obtained through crimes committed in the Russian Federation.
"The above-mentioned persons are suspected of taking part in dishonest management of state property or state interests or of taking bribes."
The Swiss general prosecutor, Mr Bernard Bertossa, has opened a criminal investigation into charges of money-laundering.
The 12-page document details the banks, their location, the account numbers, and the dates of the alleged transactions involved in what has become known as the Mabetex affair, although the Swiss authorities now call it "the presidential administration-Mabetex affair".
The contracts refurbishing the Kremlin were awarded by Mr Borodin to two Swiss-based sister companies: Mabetex, owned by a Kosovo Albanian, and Mercata Trading and Engineering, run by the Russian businessman, Mr Viktor Stolpovskikh, who also owned Lightstar and set up the Isle of Man account.
In January, a year after the investigation began, the Swiss issued an international arrest warrant for Mr Borodin. One of Mr Putin's first acts on becoming President on New Year's Eve was to move Mr Borodin out of the Kremlin, making him secretary of the Russia-Belarus union.
Mr Borodin denies the charges and the Russian prosecutor's office has exasperated the Swiss by playing for time. The leak of the Swiss document on the eve of Mr Roschacher's visit was seen as a mark of their frustration and an attempt to put pressure on the Russians.
The Swiss will have difficulty bringing a successful prosecution unless the Russians say their laws have been broken and that the "commissions" paid to Mr Borodin and others were illicit. But Mr Ustinov, appointed by Mr Putin earlier this year, has yet to order a criminal investigation.
The Swiss document asks the Russians to say whether "the activities described are in breach of Russian criminal law on taking bribes and/or abusing power".
Mr Borodin's office is said to have paid Mercata Trading $492 million for refurbishing the Kremlin and the Chamber of Audits in Moscow. Mercata transferred $62.5 million to the Lightstar Isle of Man account.
The Swiss document makes only passing reference to Mabetex, despite earlier allegations that its boss, Mr Beghjet Pacolli, provided credit cards to the Yeltsin family in return for winning the contracts.
The Russian prosecutor's office confirmed this week it had received the Swiss document, but said it would not respond to papers received by fax. Mr Devaud said he had sent it by fax "because of the urgency and nature of the case . . . and to speed up the investigation".
But the signs are that Mr Ustinov is under orders to block the investigation.