"Vasily Aleksanyan has been detained and is currently being questioned at the Prosecutor General's office," Gevorg Davgyan said.
A Moscow court ruled earlier Thursday that prosecutors could charge Aleksanyan with embezzling more than 12 billion rubles (about $460 million) from Yukos production unit Tomskneft and the funds of some other oil companies, and with laundering another 12.7 bln rubles ($460.8 mln) through his personal account in a Swiss bank.
Aleksanyan denied any wrongdoing ahead of the ruling.
"As you can see, I am staying in Russia, am not trying to flee the country, and I do not believe I am guilty of anything," said Aleksanyan, who as head of the Yukos legal department acted for ex-Yukos CEO Mikhail Khodorkovsky and former Yukos-Moscow president Vasily Shakhnovsky at their trials.
Aleksanyan said the decision to charge him could be linked to his appointment as Yukos executive president, a move the Yukos board endorsed Tuesday.
The board said Aleksanyan would be entrusted with representing the interests of stakeholders, including creditors and shareholders, and ensuring that the company's assets were protected.
"It is the Company's hope that Mr. Aleksanyan will not be unduly prevented from carrying out this very important task for all concerned," Yukos said in a press release Wednesday.
The official, whose apartment and country house were searched yesterday by the investigators, did not appear in court this morning.