An archaic accounting system that relies on note cards and filing cabinets has left the Allegheny County Sheriff's Office without the means to track revenue from thousands of tax-lien sales, according to a controller's audit released yesterday.

The sheriff's office also overcharged $2.5 million for fees associated with the sales between 2003 and the end of last year, and it has delayed payments to tax collection agencies, municipalities, school districts and the county's general fund.

County Controller Mark Patrick Flaherty said he had discovered no evidence of illegal activity. But weak oversight could invite corruption in a county row office that has already seen three high-ranking deputies be convicted of federal crimes in the past year.

"It's like parking the car, rolling down the window, putting the keys in, and leaving $1,000 on the dashboard," Mr. Flaherty said.

Still, the controller offered some praise for Sheriff Pete DeFazio and his new chief deputy, William P. Mullen Jr., who are already trying to address the issues raised in the audit. A private consultant is moving all information in paper files to a computerized system.

Deputy Chief Mullen, a veteran of the Pittsburgh Police Bureau, joined the sheriff's office in April. He replaced Dennis Skosnik, who this month was sentenced to more than five years in a federal prison after pleading guilty to wire fraud, bribery, mail fraud, money laundering and tampering with a witness.

"We're grateful to the controller for doing this audit," Deputy Chief Mullen said. "It's bringing us into the 21st century. It's long overdue."

In recent years, the office has been overwhelmed with sheriff's sales, which take place the first Monday of every month at the Allegheny County Courthouse. Between 1997 and 2005, annual sales jumped from 1,361 to 4,251, placing huge strains on the long-standing practice of recording transactions on small note cards.

An audit released in 2003 noted similar problems with accounting practices in the sheriff's office.

Mr. Flaherty, who became controller 2¹/₂ years ago, has been conducting audits of every county row office. He decided to focus on sheriff's sales when municipal officials told him they weren't receiving money for their properties.

Some specific items included in the audit:

The office couldn't provide a listing of how much it owes to third parties, such as school districts and municipalities.

Of 55 sheriff's sales transactions sampled by the controller's auditors, only 10 were paid on time.

The office didn't have records for eight voided cash register transactions totaling $23,919. Also, no security camera observes the register.

The office apparently never cashed some checks intended to pay for sheriff's sales, while some cancelled checks are missing.

One section of the audit focuses on a range of fees that the sheriff's office needlessly collects, including an extra $30 charge for advertising property sales that isn't legally required. From 2003 to 2006, those charges amounted to $299,450. The money is sitting in the office checking account.

In total, the sheriff's office collected $2,505,356 in fees that the auditor's office said were unnecessary. About $1.8 million was paid to the county's general fund.

Pam Goldsmith, a spokeswoman for Mr. Flaherty, said the county Law Department would decide how to handle the overpayments.

Deputy Chief Mullen said the sheriff hopes to be able to repay the money. First, however, his office must introduce its new accounting system.

The firm Schneider Downs is helping to compile all paper files into a computerized format using spreadsheets and accounting software. The process could be completed by early next year.

Deputy Chief Mullen said he also hopes to computerize other parts of the sheriff's operations, including the collection of fees for concealed-weapons permits. Sheriff's cars soon will come equipped with laptop computers.

The controller's audit also suggests that the county treasurer take over the responsibility of receiving and making payments for the sheriff. Mr. Mullen said his office is exploring that possibility.

The office recently moved its money into a National City checking account with a significantly higher interest rate.

When the updated accounting system is ready, the controller, with the help of a private firm, may undertake a more thorough audit.

"This is just the first episode," Mr. Flaherty said.