Now District Attorney Seth Williams is involved, reviewing the inspector general's findings - which also implicate five other city employees who handle parking ticket appeals - to determine whether there was any criminal wrongdoing.
Alternatively, the matter may only constitute a violation of the city's ethics rules, including the acceptance of gifts (employees are prohibited from accepting them). Toward that end, the city's Board of Ethics, which has the authority to issue financial penalties, is reviewing the inspector general's findings as well.
Cary Borish, the partner and son of Marathon Grill founders Jay and Sheryl Borish, referred calls to a spokeswoman Friday.
"Marathon is not commenting on the facts in this matter. Marathon is relying on the authorities to handle the investigation," spokeswoman Clare Pelino wrote in an e-mailed statement. She declined to answer questions.
The upscale diner chain, which serves sandwiches as well as fish, steaks, pastas, and liquor - has six locations. Founded in 1984 in the Roosevelt Mall in Northeast Philadelphia, Marathon also runs a catering business.
Among the chain's frequent clientele are workers from City Hall and neighboring municipal buildings, where parking is scarce.
Marathon is one of about four food vendors that the city courts pay to provide lunch to deliberating jurors.
In recent years, the city has paid the restaurants $75,814, according to the City Controller's Office.
Marathon was not publicly identified this week when Inspector General Amy Kurland announced that six city employees had been fired or unexpectedly left their jobs as a result of a ticket-fixing investigation.
Among them was Clorise Wynn, deputy director of the Bureau of Administrative Adjudication, a division of the Finance Department that oversees the appeal of tickets issued by the Parking Authority.
"They delivered food to her at home and at work, sometimes for free and sometimes at reduced cost," Kurland said Friday. She would not name the restaurant but said it cooperated with her office's investigation.
In addition to dismissing $50,000 worth of parking tickets - accumulated since 2006 - the investigation also found that Wynn got rid of hundreds of tickets for friends and 35 for her daughter.
Regarding Marathon's tickets, Kurland said, "We couldn't prove the restaurant did anything wrong. If there was a quid pro quo or there was bribery, that is a decision the district attorney makes, not us."
Kurland also said it was unusual for Wynn to be handling Marathon's ticket complaints.
That job generally fell to another employee charged solely with handling delivery-oriented businesses, which tend to rack up tickets.
That employee said he or she did not handle the Marathon account because "Clorise took that one,'" according to Kurland.
In a brief interview outside her home Friday, Wynn said she received no free food from Marathon and had done nothing illegal.
"I did the best job that I could. When I went down there, there was no leadership at all," said Wynn, who was paid about $100,000 a year and said she was preparing to move out of state. "I know I did a good job cleaning up in there."
It is uncertain whether the city will try, or should try, to recover any of the $50,000.
"There are a whole bunch of tickets. We are not sure which ones were dismissed inappropriately," Finance Director Rob Dubow said. "We need to go back and actually go through the tickets and look at them one by one."
Marathon has faced legal troubles in the past.
In 2005, the U.S. Department of Labor forced it to pay $21,000 in back wages to 12 employees who had not been paid overtime or had not been paid at all.
"We're not saints," Cary Borish said at the time.
Contact staff writer Marcia Gelbart at 215-854-2338 or firstname.lastname@example.org.