( Reuters ) - Russian police detained Deputy Finance Minister Sergei Storchak on Friday as part of a criminal investigation, the Finance Ministry said.
Storchak is responsible for Russia's debt policy and oversees the $148 billion stabilization fund, which collects windfall revenues from oil exports.
"The detention took place outside the ministry. It may be related to criminal cases against a third party, not finance ministry officials," the ministry said in a statement.
It said it had not received any official documents from law enforcement agencies related to the detention and expressed hopes the investigation would be objective.
Earlier, a senior police source told Reuters Storchak was detained on criminal charges but declined to give any details of the case.
A source close to Finance Minister Alexei Kudrin told Reuters he "could not rule out" that the detention was part of a campaign against Storchak's powerful boss ahead of next month's parliamentary election.
President Vladimir Putin promoted Kudrin, his long-term ally, to the rank of Deputy Prime Minister in a reshuffle in September. Kudrin was not available for comment on Friday.
Storchak, 53, a burly official known for his abrupt manners, was appointed deputy minister in 2005. He negotiated Russia's repayment of its debt to the Paris Club of creditor nations, which it completed last year.
Ekho Moskvy radio station and Interfax news agency reported, quoting unidentified sources, that Storchak had been due to fly to South Africa on Thursday for a meeting of finance ministers of the 20 most industrialised and important emerging economies. But he did not show up on the government's plane.
Storchak last spoke publicly on Tuesday when he criticized the central bank's proposal to start using the open market to convert roubles into foreign currencies for the stabilization fund.
The source close to Kudrin said his case was not related to a criminal case against another Paris Club debt negotiator Denis Mikhailov, convicted in 2006 for accepting a $110,000 Mercedes and leaking classified documents.
"This is a new case. Not the one against Mikahilov ... this is nothing like Mikhailov's case had, no bribes and cars," the source said.
A senior Kremlin administration source was surprised at the news of Storchak's detention and also said it could be an oblique attack on Kudrin.
"It has been a long time since such a senior official was arrested. Maybe it is an attack on Kudrin," the source said.
Tass news agency quoted a source in the Finance Ministry as saying the FSB security police had searched Storchak's office in the ministry on Friday.