SAN FRANCISCO -- The San Francisco City Attorney has sent a letter to the head of City Tow demanding that the company cease "highly questionable" billing of San Francisco residents.

Dennis Herrera has recently received dozens of complaints about collection notices that went out to city residents, claiming towing and storage debts from as far back as 2001.

"The information provided to us by vehicle owners suggests that a large number of the claimed debts are not valid," Herrera wrote in the letter to Glenn McElroy, president of Pick Your Part Auto Wrecking.

The Anaheim-based company had done business in San Francisco as City Tow since 1987.

In March, the city's lucrative towing contract was given to San Francisco AutoReturn amid charges of City Tow fraud and misconduct.

According to the City Attorney's letter, City Tow has been trying to collect storage charges in cases where car owners signed over titles to the towing company, which gained ownership of the vehicles and in turn promised to waive the storage charges.

"We request that City Tow suspend such collections activities immediately," Herrera wrote.

The letter also claims that City Tow violated state law in allegedly disposing unclaimed vehicles through junkyards rather than public auctions.

Herrera asked in the letter to meet with McElroy on or before Aug. 2.

McElroy could not immediately be reached for comment.

A lawsuit filed by the San Francisco City Attorney and state Attorney General Bill Lockyer in October 2002 charged that the company defrauded taxpayers of hundreds of thousands of dollars, according to the City Attorney's office.

The lawsuit remains ongoing in San Francisco Superior Court.