Bulgaria will launch extensive checks of rich property owners for possible tax evasion and moneylaundering, the government said on Thursday in a bid to avert more European Union sanctions.

The EU has already frozen millions of euros in aid to punish the Balkan member state for failing to tackle rampant corruption and organised crime. Sofia faces more sanctions this year unless it speeds up judicial reforms and enforces the rule of law.

National security officers, police and taxmen will start checking in June every owner of property worth over 500,000 levs ($325,500), the government said, without giving details.

The EU newcomer adopted a law, based on similar Irish legislation, authorising the confiscation of illegally obtained assets in early 2005. But in practice, it has so far failed to confiscate the assets of a single leading criminal.

Armoured convoys belonging to well-known crime bosses are a common sight in the country, and luxurious hotels and villas are mushrooming.

Officials at the commission for the recovery of criminal assets have blamed weak political will and sluggish court procedures for failures to convict criminals, and so seize their assets outright.

Local media quoted European Affairs Minister Gergana Passy as saying the government was determined to make changes to the law by May that would give greater powers to the commission. The EU is due to publish a new report on Bulgaria's progress this summer.

Despite numerous pledges to speed up reforms and produce results, Bulgaria has failed to convict a single senior official of corruption and has jailed only one crime boss.

Observers and diplomats say the root of the problem lies in links between politicians, magistrates and criminal groups, some of which sprang out of the communist-era secret police.