Masked police officers yesterday raided a Russian bank controlled by Alexander Lebedev, the owner of The Independent and the new i title, in a move described by an aide to the billionaire as a "circus".

Mr Lebedev was inside the headquarters of the National Reserve Bank when about 30 officers, many of them carrying semi-automatic weapons, entered its offices in central Moscow shortly after midday local time, jumping turnstiles before commencing a search through company documents.

A spokesman for the Moscow city police said the search, which was conducted by a group of about 10 suited investigators accompanying the balaclava-clad marksmen, was part of an "ongoing criminal investigation". Investigators later said they were looking for papers related to Rossiyskiy Kapital, a lender bailed out by the bank in 2008.

High-profile raids involving the seizure of computers and documents are a common tactic among Russia's law enforcement agencies. The practice is widely seen as a tool to intimidate targets, often on behalf of rival businesses or as a precursor to attempts to secure the outright seizure of a company.

Sources close to Mr Lebedev said the raid could be linked to calls from the billionaire for Yuri Luzhkov, the former mayor of Moscow who was sacked in September, to face corruption charges. Mr Luzhkov remains an influential figure but is increasingly dogged by graft claims. He denies any wrongdoing.

Mr Lebedev, 50, is also the financial backer of Novaya Gazeta, the Moscow-based opposition newspaper where four journalists have been murdered since 2001. The title has regularly ruffled feathers in the Kremlin with its investigations into corruption and scrutiny of the activities of state agencies. The paper reported that three of the investigators involved in yesterday's raid demanded a meeting with Mr Lebedev shortly after entering the building. The siege, which saw armed officers stationed at the doors of the bank, was lifted after two hours without arrests.

Artyom Artyomov, Mr Lebedev's spokesman, said no claims had been made against Mr Lebedev or the bank and criticised the ostentatious nature of the "masky-show" – a term coined in the 1990s for raids on Russian businesses by police. He said: "We don't see any reason to organise this circus. Why do they come in here with their guns and masks? If they need a file they can come with a piece of paper and just ask."

Dmitry Muratov, editor-in-chief of Novaya Gazeta, told Bloomberg: "There's no way to look at this other than as an attempt to intimidate Lebedev. He promotes civil society and a free press. This doesn't please the security men in power."

The raid came as the jailed former oil tycoon Mikhail Khodorkovsky told a judge considering new charges against him and a business partner that the fate of all Russians rested on the outcome of his trial for embezzlement, expected next month.

Mr Khodorkovsky, 47, whose supporters say he is being kept behind bars as long as possible after he funded opposition parties, said his case was a litmus test for the rule of "law and freedom" in Russia. If convicted, he faces a further seven years' imprisonment.