The Internal Revenue Service is accusing a Kaneohe sports and luxury car dealer of helping pimps and prostitutes launder money by taking large, unreported cash payments for car sales.

The U.S. attorney filed a criminal complaint in federal court Monday charging William Bartenstein with failing to file a currency transaction report with the IRS for accepting more than $10,000 in a single cash transaction as required by law for the sale of a car.

Bartenstein owns and operates the Corvette Center Ltd., which specializes in selling Chevrolet Corvettes and other sports and luxury cars.

The IRS said it began investigating Bartenstein in 2003 after an informant reported that Bartenstein was willing to launder money or structure large cash transactions to evade reporting requirements. The informant is a former car salesman and manager who previously helped the IRS bring criminal cases against other individuals and five dealerships.

At the start of the investigation, the IRS said it noticed Bartenstein never reported doing single cash transactions of more than $10,000 while people from whom he purchased cars with cash did report the transactions.

The IRS said it also noticed, in a joint investigation with the Honolulu Police Department, that suspected pimps and prostitutes and a suspected narcotics trafficker were driving cars bought from Bartenstein.

The IRS said an undercover IRS special agent posing as a pimp later recorded Bartenstein telling the agent he knew other pimps and has sold them cars without revealing their identities or reporting the cash transactions to authorities.

According to a transcript of the recording, Bartenstein told the agent he can register the vehicle in somebody else’s name and list himself as a lien holder to prevent the government from seizing it.

The IRS said the agent paid $40,000 cash to buy a truck from Bartenstein, who then registered the vehicle under a fictitious name.