Banned TNK-BP chief Robert Dudley has lodged an official complaint over the treatment of the company in a letter to five federal agencies.

"There has been an abuse of power by the State Labor Inspectorate," Dudley wrote in the letter dated Aug. 19 and sent to five governmental bodies, including the labor inspectorate, Prosecutor General's Office, the Federal Security Service and an anti-corruption council.

Dudley said seven inspections made at TNK-BP "when there is a developing corporate conflict between the Russian and foreign shareholders over a short period of time" indicates that the inspectorate is interested in the outcome.

A Moscow court this month banned Dudley from working in Russia for two years. The move was the latest blow to hit the troubled firm, whose four Russian billionaire shareholders owning half of the company are at loggerheads with BP, which owns the other half, over management and strategy.

The labor inspectorate chief, Mikhail Malyuga, denied Dudley's claims of bias. "All the checks that took place at the firm were done by the law," he said.

TNK-BP has been deluged with a wave of tax, labor and police inspections, several lawsuits and visa problems. Analysts say repeated inspections and Dudley's ban mean a state-controlled company could be eyeing TNK-BP.

"The unambiguous conclusion is that the said officials were carrying out somebody's orders, and we request that this be investigated," Dudley said.