Masked police raided offices of a bank controlled by billionaire Alexander Lebedev, the Kremlin critic who owns the Novaya Gazeta opposition weekly in Moscow and Britain’s Evening Standard and Independent newspapers.

The search of Lebedev’s National Reserve Bank was part of an “ongoing criminal investigation,” police spokesman Viktor Biryukov said in comments reported by state-run RIA Novosti news service and confirmed by his office. Biryukov didn’t elaborate.

Dozens of armed officers surrounded and sealed off the building before noon, while three men in civilian clothes, also clad in balaclavas, entered and demanded a meeting with Lebedev, Novaya Gazeta said on its website. The siege was lifted at about 2 p.m. local time without arrests, the newspaper said.

A call to Lebedev’s mobile phone at 6:15 p.m. local time was answered by his spokesman, Artyom Artyomov, who said the billionaire was in Moscow while city police investigators continued the search.

“The armed men are gone, investigators continue their work,” Artyomov said by phone. “This is a very strange demonstrative action whose motivation is unclear,” he said. Police made no claims against the bank or Lebedev, he said.

‘Attempt to Intimidate’

“There’s no other way to look at this other than as an attempt to intimidate Lebedev,” said Dmitry Muratov, Novaya Gazeta’s editor-in-chief. “He is completely independent and promotes civil society and a free press,” Muratov said by phone. “This doesn’t please the security men in power.”

Investigators said they were searching for documents related to Rossiisky Kapital, a lender Lebedev bailed out after the 2008 collapse of Lehman Brothers Holdings Inc., according to Novaya Gazeta.

Lebedev, 50, a former KGB spy who once worked undercover in London as an economic attaché, bought into Novaya Gazeta in 2006 with the support of former Soviet President and Nobel Peace Prize winner Mikhail Gorbachev. Forbes magazine estimated Lebedev’s net worth at $2 billion this year, making him the 488th richest person in the world.

The National Reserve Bank building in southwest Moscow is also home to Rusnano Corp., the government’s holding company for nanotechnology ventures.