CLEVELAND, Ohio -- Two road-salt vendors swindled Ohio taxpayers out of tens of millions of dollars, according to a blistering report released Thursday.

The findings from Inspector General Thomas Charles allege that Cargill Deicing Technology and Morton Salt Co. refused to aggressively challenge each other's bids.

Because of the anti-competitive alliance, the

overpaid between $47 million and $59 million for salt over the last decade, the

states.

"Evidence that Cargill and Morton engaged in sham bidding is revealed in consistent bidding patterns in which the same company has continued to win its incumbent-client counties year after year despite significant increases in prices over time," the inspector general wrote.

In written statements, spokesmen for both companies denied wrongdoing.

Among the findings are allegations that Cargill entertained several ODOT and Cleveland-area officials who have the power to recommend or buy salt. The review is based on a nearly two-year investigation and has been referred to the U.S. Department of Justice, the state's attorney general and ethics commission, and to Cuyahoga County Prosecutor Bill Mason.

Officials were schmoozed with food, football tickets and golf, according to the report.

A Cargill representative is accused of treating the Bedford Heights service director and his assistant to a 2008 Browns game around the time the southeast suburb ordered hundreds of tons of the company's enhanced salt. The report states that Director Nick Baucco and Assistant Director Frank Paparone each received a $75 ticket to the game.

Expense reports from Cargill revealed that Baucco and Paparone also received more than $400 worth of meals, drinks and other "gratuities" between May 2006 and May 2009.

Baucco acknowledged to the inspector general's office that he did not reimburse the Cargill manager for the tickets but said the gesture was "not a quid pro quo" for the city's business. Baucco and Paparone could not be reached for comment Thursday evening.

In Twinsburg, Roads Superintendent Dennis Koballa allegedly received Browns and Indians tickets and other gifts totaling more than $400 from Cargill after recommending his city buy the company's brine maker in 2006. Koballa, who could not be reached Thursday, denied that the gifts influenced his recommendation.

In less detail, the report and an

(PDF: See exhibit 83) say an official from a trucking company that hauled salt Cargill provided meals valued at less than $50 or cocktails to former Cuyahoga County Commissioner Jimmy Dimora, Cleveland City Council President Martin J. Sweeney, Northeast Ohio Regional Sewer District Executive Director Julius Ciaccia and two Cleveland officials.

Dimora has pleaded not guilty to 26 charges in an unrelated federal probe of public corruption that focuses heavily on a pay-to-play atmosphere in county government.

Reached by telephone late Thursday, Dimora referred a reporter to financial disclosure forms filed annually with the Ohio Ethics Commission. The report from 2007, the year the trucking official reported entertaining Dimora, lists him as the giver of an unspecified meal.

Ciaccia, formerly the head of Cleveland's Water Department, said he "never had a meal" with the trucking official, though the businessman reported a steakhouse lunch.

Sweeney did not return telephone calls seeking comment.

City Hall spokeswoman Andrea Taylor, responding to word that Streets Commissioner Randell Scott and Chief Operating Officer Darnell Brown were noted in the report and attachment, said the city does not directly buy its road salt.

"The city doesn't have anything to do with that other than to tell ODOT how much salt we want," Taylor said.

Plain Dealer reporters John Caniglia and Tonya Sams contributed to this story.