Jailed Russian oil tycoon Mikhail Khodorkovsky claims Kremlin pressure forced  Big 4 accounting firm PwC (PricewaterhouseCoopers) to adjust audits on the dismantled oil firm Yukos.

Khodorkovsky who came to prominence during the chaotic privatisation of Russian state industries in the aftermath of the collapse of the Soviet Union, was jailed for tax evasion in 2003 for 8 years, after giving financial support to political opponents of then president, Vladimir Putin. His publicly listed oil company was dismantled and divided between state enterprises.

Russian prosecutors in 2007 charged Khodorkovsky with embezzlement of the total oil production of Yukos between  1998 and 2003. Conviction would keep him behind bars for decades more.

In March 2007, police raided PwC’s Moscow office and the Interior ministry said it was launching a criminal investigation into alleged tax avoidance by PwC. The latter denied any wrongdoing.

The Wall Street Journal says Douglas Miller, the main PWC partner on the Yukos account, left Russia as the pressure rose but in April 2007, he returned to Moscow to speak to investigators at the behest of PWC. Case records show he was questioned as a witness at the Moscow offices of the Prosecutor General five times over 10 days in early May 2007. He wasn't charged with any crime.

Transcripts of the questioning were reviewed by The Wall Street Journal. They indicate that prosecutors were seeking evidence to support the embezzlement case that they had brought against Khodorkovsky and his partner, Platon Lebedev, in early 2007.

At a sixth interrogation on June 4, 2007, prosecutors asked Miller about PWC's plans to withdraw its audit opinions for Yukos's financial statements. The Journal reports Miller answered that there were active discussions of the issue going on at higher levels of PWC.

Within weeks, Russian prosecutors closed their investigation of alleged tax avoidance by PwC.

The Financial Times reports Douglas Miller told prosecutors on June 4th that he believed information revealed during the investigation shows Yukos management misled PwC and would recommend withdrawal of 10 years of audits.

The defence lawyers argue that without the audits being withdrawn, the prosecutors would have had difficulty pursuing the charges  - - even in a Russian court - - as all the oil production the investigators claimed were embezzled had been accounted for and consolidated into the Yukos oil group by PwC under US accounting principles.

The Journal says as Russian prosecutors prepared to call Miller as a witness in the second case against Khodorkovsky in the spring of 2009, he left Russia and PWC.

Khodorkovsky's attorneys have requested the US District Court in Manhattan to order PwC to produce documents related to its decision. They have also requested the California Board of Accountancy to revoke the license of Douglas Miller.

Apart from keeping Khodorkovsky and his partner in jail, it is argued that Russia would use a guilty charge of embezzlement to bolster its defence in several international cases related to the seizure of Yukos.