SOFIA (Reuters) - Ex-energy minister Delyan Dobrev voluntarily gave up his parliamentary immunity on Monday after Bulgarian prosecutors asked lawmakers to strip him of it, and denied any wrongdoing over the loss of state funds in a canceled nuclear project.

Prosecutors accuse Dobrev, who was energy minister in the first government of Prime Minister Boiko Borisov, of failing to take steps to stop payments to a consultant company engaged with the Belene nuclear project after it was canceled in 2012.

"The request is based on evidence collected by the Sofia City Prosecution for a crime committed by Delyan Dobrev when he was economy and energy minister, which caused damages worth 4.56 million euros ($4.9 million) to the state energy firm NEK," the chief prosecutor said in a statement.

Dobrev, now head of parliament's energy commission, responded by ceding his immunity before lawmakers could act, and declared that he had done nothing wrong.

"I am not guilty and that will easily be proven in court. I hope prosecutors will find the real culprits for Belene, the shadiest deal in Bulgaria's history," he told reporters.

The Balkan country canceled the 10-billion-euro Belene project on the Danube River after failing to find foreign investors and under pressure from Brussels and Washington to limit its energy dependence on Russia.

Bulgaria now must pay over 620 million euros in compensation to Russia's nuclear firm Rosatom it had contracted for the project, which many politicians and analysts say reflected high-level graft in the European Union's poorest member state.

Prosecutors have already charged another former energy minister and two executive directors at NEK in connection with the Belene project.

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(Reporting by Tsvetelia Tsolova; Editing by Mark Heinrich)