Bulgaria, the poorest country in the European Union, is also its most corrupt and the situation is getting worse, according to a damning new study published today.

"Key public institutions have been captured by private interests," the Sofia-based Centre for the Study of Democracy (CSD) think-tank said.

"Critical sectors of the public administration and the judiciary have become dysfunctional to the extent that nothing short of a drastic shake-up would have any impact," it said.

It said the number of corruption cases processed by law enforcement and punished was "negligible compared to the real magnitude of the problem".

Public officials' susceptibility to corruption has also reached some of the highest levels since the CSD starting carrying out its surveys in 1999, with one in five Bulgarians admitting to paying a bribe last year.

Administrative and political corruption have shown little signs of abating in the past two decades, not even since Bulgaria joined the EU in 2007, the report said.

It added that government policy is often hijacked by powerful businessmen and bent officials, driven by greed rather than the common good and affecting whole sectors of the economy.

Interior Minister Rumyana Bachvarova admitted that Bulgaria has a problem.

"The corruption environment in the country is developing quicker than the ability of the state institutions to counter it," she said after the release of the report.

Deputy premier Meglena Kuneva said a new anti- corruption bill is now going through parliament. But Justice Minister Ekaterina Zaharieva said Bulgaria often lacks the right people to clean things up on the ground.