MOSCOW (Reuters) - Armed Russian police on Tuesday raided the offices of a pro-democracy movement founded by outspoken Kremlin critic Mikhail Khodorkovsky, a move they said was part of a criminal investigation into the former tycoon and his associates.

Former Russian tycoon Mikhail Khodorkovsky speaks during a Reuters Newsmaker event at Canary Wharf in London, Britain, November 26, 2015. REUTERS/Peter Nicholls

Khodorkovsky, whom police accused this month of organizing a contract killing in 1998, interpreted the latest pressure on him as payback for his criticism of President Vladimir Putin.

“Searches at the Open Russia (movement) after my meeting with journalists,” the 52-year-old wrote on his official Twitter feed. “A repeat of 2003. Putin has become predictable.”

Khodorkovsky’s Open Russia movement, which says it unites groups and individuals who want Russia to change, said police had also searched some of its staff members’ apartments in Moscow and St Petersburg and taken away documents.

Khodorkovsky has criticized the Kremlin repeatedly in recent months, accusing Putin of leading Russia into a 1970s Soviet-style period of stagnation that could eventually trigger its collapse.

Putin freed Khodorkovsky, once Russia’s richest man, in 2013 after he had spent a decade in jail for fraud, a charge that Khodorkovsky said had been fabricated to punish him for funding political opposition to Putin. The president has said he regards the businessman as a common thief.

Russia’s Investigative Committee said Tuesday’s raids were part of a criminal investigation into the former shareholders and management of Yukos, the now defunct oil major that Khodorkovsky ran until he was arrested at gunpoint in 2003.

Investigators said the latest case centered on allegations of oil theft and money laundering, and was related to a legal standoff between the Russian government and former Yukos shareholders.

An international arbitration court ruled last year that Russia must pay $50 billion to the firm’s former shareholders for expropriating its assets.

The shareholders began to seize bank accounts and properties in Paris and other parts of France belonging to the Russian Federation in June this year. A French court last week rejected Russia’s request to suspend the seizures.

The Investigative Committee said Tuesday’s action was part of an exercise to check whether the shareholders had acquired Yukos shares legally in the first place.

Khodorkovsky, who spends much of his time in London, likened the raids to repression in the Soviet era.

“The decay had entered its final stage,” Khodorkovsky told the Ekho Moskvy radio station. “We are all familiar with this from the time of (Soviet leader Leonid) Brezhnev.”

Earlier this month, Russian police said they had uncovered evidence suggesting Khodorkovsky had ordered the 1998 contract killing of the mayor of an oil town in Siberia.

Khodorkovsky denies any involvement.