Police in Russia have raided the offices of a company owned by Yelena Baturina, the wife of former Moscow Mayor Yuri Luzhkov.
Officials said the Inteco firm had been searched as part of an investigation into suspected embezzlement linked to a 13bn rouble (£275m; $444m) bank loan.
Mrs Baturina, who is believed to be Russia's richest woman, said the raid was an attempt by the authorities to "put pressure" on her and her husband.
Mr Luzhkov was sacked last year.
Mr Luzhkov, who was fired after a public confrontation with President Dmitry Medvedev, has been accused of using his influential position to help his wife amass her fortune.
Both he and Mrs Baturina, whose wealth is currently estimated to be about $1.1bn, deny the claim.
Armed policemen in masks raided the Inteco offices on Thursday morning.
Employees were reportedly locked in one room, as the police searched for documents in the accountancy department of the firm.
The offices of the Bank of Moscow and the homes of its directors were also raided.
The investigation was launched last month into a deal under which the Bank of Moscow lent 12.76bn roubles to a little-known real estate firm.
The firm then bought land from Mrs Baturina's debt-ridden Inteco at what investigators believe was an inflated price.
Inteco then allegedly used the proceeds to pay off a large chunk of its maturing debts and stay solvent.
Inteco has always insisted that it acted in accordance with Russian laws.
On Thursday, Mrs Baturina called the raids a political provocation.
"I know for certain that these searches have no relation to either our company or the Bank of Moscow," she told Russia's Interfax news agency.
"This is simply an ordered (raid) and a form of (political) pressure."