Russia's richest man has appeared at a court hearing in Moscow ahead of his trial for tax evasion and fraud.
Khodorkovsky is being held in a notorious Moscow jail
Mikhail Khodorkovsky arrived from prison at the small court in the north of the city under heavy police guard.
Lawyers say the prosecution against him is political because he funded opponents of President Vladimir Putin.
Yukos, the oil firm Mr Khodorkovsky once headed, also went to court on Friday to challenge a massive tax bill which it says could lead to bankruptcy.
New Yukos head
The tax ministry this week won a key court decision requiring Yukos to pay the equivalent of $3.5bn in back taxes and fines.
Mr Khodorkovsky's case - which could go on for months - was adjourned until 8 June while the case against Yukos was adjourned until 31 May.
Mr Khodorkovsky's business partner, Platon Lebedev, was also set to face trial but proceedings in his case were delayed until 8 June, Interfax news agency reports.
A Russian newspaper, Vedomosti, says key Yukos shareholders have asked Mr Khodorkovsky's successor as chief executive, Simon Kukes to leave his post by the end of June.
An American, Steven Theede,
who is currently the group's operations director is tipped as his replacement, said Vedomosti.
Yukos has shed half its value following the arrest of Mr Khodorkovsky and Mr Lebedev last year.
On Friday shares in the company dropped nearly 11%, having lost 12% the previous day.
A small and shabby room in Meshchansky Court was the setting for Russia's most controversial legal case in recent years, BBC reports said.
Mr Khodorkovsky's mother, Marina Filipovna, climbed on a bench at the courtroom to try to catch a glimpse of her son.
"My son knew what was in store for him in Russia when he refused to go abroad," Itar-Tass news agency quoted her as saying.
If convicted, Mr Khodorkovsky could be given a 10-year prison sentence while Yukos may be transferred to state control.
Wealth v power
Mr Khodorkovsky has a personal fortune estimated at $15bn but many believe he is being prosecuted less for how he acquired his wealth than for the way he used it - namely to challenge the power and authority of President Putin.
The trial is seen as pitting Russia's richest man against its most powerful.
President Putin has insisted that the case has been brought by prosecutors with no interference from the government.
Correspondents report little sympathy for the fate of "oligarchs" like Mr Khodorkovsky among ordinary Russians, the vast majority of whom saw their living standards plummet with the collapse of communism.
But the case has raised concern within the business community and abroad.