The Czech Republic's main opposition party demanded on Thursday that Prime Minister Petr Necas step down after police raided government offices, seized documents and detained a woman who for years has been one of his closest aides.
Necas said he would not consider resigning after the raids, but the investigation is a severe blow to his government, which does not have a stable majority in parliament and has already come close to collapsing several times.
Hundreds of officers from the Organized crime unit, some armed and wearing balaclavas, conducted sweeps of the government headquarters and the Defense Ministry. They also searched safe deposit boxes in a bank, seized documents at the capital's city hall, and raided private homes.
One anti-graft campaigner said it was the biggest operation in the past 20 years to tackle corruption in the Czech Republic, a European Union member of 10.5 million people.