This is all about pressure and intimidation

Media-Most spokesman

Mr Gusinsky, one of Mr Putin's fiercest critics, is accused of fraud in a case involving his company Media-Most. He has already ignored one summons.

Officials have threatened to issue a warrant for his arrest if he fails to turn up again.

A spokesman for Mr Gusinsky denounced the case as politically-motivated and plain blackmail.

"We are certain that any efforts to influence Media-Most by undoubtedly illegal methods are doomed to collapse," the company said in a statement.

'Large-scale theft'

Both cases are thought to reflect President Vladimir Putin's distaste for a small group of so-called oligarchs who amassed vast wealth through privatisation deals following the collapse of communism.

Mr Berezovsky denies wrongdoing

Mr Putin has said he will not allow big businessmen opposed to post-Soviet reforms to stand in his way.

A statement from prosecutors investigating the Aeroflot case said investigators had "gathered sufficient evidence to announce charges of large-scale theft".

Deputy Prosecutor-General Vasily Kolmogorov told state television that Mr Berezovsky was a "main figure", but not necessarily a suspect, in the case.

Out of favour

Mr Gusinsky was arrested and jailed for four days in June after being questioning in connection with embezzlement charges. He left the country immediately after the accusations were dropped.

The case sparked condemnation of Mr Putin, who was accused of seeking to influence Media-Most's coverage of the Chechnya conflict.

Mr Berezovksy and Mr Gusinsky own interests in two of Russia's three national television networks.

The former, who was a member of former President Boris Yeltsin's inner circle, has fallen from grace since President Putin took over in January.

The latter fell out with the Kremlin shortly after he and other magnates supported President Yeltsin's 1996 re-election effort.