Prosecutors launched an investigation earlier this month into allegations of abuse of power by former Interior Minister Yuriy Lutsenko. But his spokeswoman, Larisa Sargan, said the four prosecutorial investigators who showed up at his apartment at 6 a.m. gave no explanation for the search.

A spokesman for the Prosecutor General's Office, Yuriy Boychenko, said Lutsenko is accused of providing firearms worth 143,000 thousand hryvna (US$28,000; €22,000) to people who had no gun licenses. He said he had no information about the search.

Lutsenko was a leading organizer of massive street protests against alleged fraud in a 2004 election that gave victory to presidential candidate Viktor Yanukovych. The protests, known as the Orange Revolution, helped prompt a repeat vote that brought pro-Western President Viktor Yushchenko to power.

Lutsenko subsequently spearheaded corruption investigations into some of Yanukovych's closest allies.

Lutsenko has come under pressure since the Russian-leaning Yanukovych took over the premiership last year, and he was fired by the parliament in December. After his dismissal, Lutsenko organized a political movement, People's Opposition, which has held rallies across Ukraine.

Last November, a Kiev court found Lutsenko guilty of corruption _ a ruling his lawyer said was politically motivated _ and sentenced him to pay a fine of just over US$65 (€49).

Yushchenko is in an awkward a power-sharing arrangement with Yanukovych.