AUBURN — A former Lewiston used car dealer pleaded not guilty Thursday to a slew of charges related to his business.

, 59, of Turner owned U-Turn Auto Sales on Lisbon Street in Lewiston. He was indicted last month by an Androscoggin County grand jury on 15 counts of aggravated forgery and one of aggravated theft. He’s accused of selling at least 15 of his customers vehicles that still had outstanding liens to his creditors from whom he bought the cars. The sales took place over eight months, ending in February 2014.

Each of the 16 charges is a Class B felony, punishable by up to 10 years in prison and up to $40,000 in fines.

Pulkkinen denied the charges Thursday at his arraignment in Androscoggin County Superior Court and asked for a court-appointed lawyer.

He was released on his own recognizance, but was told he could only work in car sales under supervision. He is not allowed to engage in financial transactions, a judge said.

The Maine Bureau of Motor Vehicles did a monthslong investigation, according to a news release from that agency.

A detective at the agency said the bureau received several complaints last summer from people who said their vehicles were being repossessed even though they hadn’t been aware of any money owed on the vehicles.

Instead of repaying the lender he used to buy the cars at the time of resale, Pulkkinen used the money to pay other bills and didn’t provide the vehicle titles to the people who purchased the cars, an agency investigator said.

He cautioned car buyers to ask to see the vehicle titles to verify they are clear of liens.

Twenty-three consumers were affected in this case. With the help of the bureau’s Vehicle Services Division and the Bureau of Insurance, the state was able to invoke the dealer’s bond on the vehicles to pay back the lender so he would release the titles to the consumers who had purchased the vehicles, according to the agency.

U-Turn Auto Sales was formerly on Lisbon Street in Lewiston and moved to Sabattus Street by the time Pulkkinen’s dealer license was suspended last summer.

The grand jury indicted Pulkkinen on the theft charge, based on the charge that he sold mortgaged property, and charged him with forgery for allegedly lying on the title applications.

In August 2014, Pulkkinen was warned that he faced loss of his license unless he provided proof of workers’ compensation insurance. The company was dissolved by the state in October 2014 after failing to maintain workers’ comp insurance and/or pay penalties.