CHICAGO (CBS) – A 10th Chicago police officer has been indicted in the FBI’s ongoing investigation of a scheme in which tow truck operators were paying bribes to cops who steered them work.

CBS 2 Investigator Pam Zekman first exposed how tow truck drivers were paying off cops who arranged for them to tow away cars damaged in traffic accidents.

Gregory Garibay, an 18-year veteran of the Chicago Police Department, was charged Friday with mail fraud and attempted extortion.

He’s accused of scheming to defraud insurance companies by filing a false accident report in one accident, staging another accident, and taking $2,200 in extortion payments from a tow truck operator who was cooperating with the FBI.

The tow truck operator said in an exclusive interview how he inflated towing, storage, and other fees charged to accident victims; in order to cover the cost of corruption.

“We had to pay the cops in order to get the tows; $400 or more a car,” he said.

The FBI’s “Operation Tow Scam” also uncovered evidence of some cops staging accidents to make more money. All it took in those cases was finding a couple damaged cars, bringing in a crooked insurance adjustor, and filing a falsified police report.

Staged accidents cost more.

“They’d come there, write the report, pay them some money right there on the spot – $2,000, $3,000 – and that was it,” the tow truck operator said.

Garibay, 44, has been stripped of his police powers. If convicted, he’d face a maximum sentence of 20 years in prison and a fine of up to $250,000.

The federal probe already has led to convictions of seven police officers, two tow truck drivers, and one other person.