Ohio state Treasurer Josh Mandel (R) may have violated campaign finance law by using a vehicle owned by his 2012 Senate campaign after the campaign was over, according to the Associated Press.

The vehicle was totaled in an accident in March, but the accident was never reported.

Mandel, considered a rising GOP star in the Buckeye State, lost to Sen. Sherrod Brown (D-Ohio) by 6 percentage points.

AP reports:

Republican Josh Mandel has kept two traffic accidents quiet since becoming Ohio treasurer in 2011 - including one that raises a potential violation of federal campaign finance law.

Law enforcement reports obtained by The Associated Press show one crash in March near Toledo and one in April 2011 in downtown Columbus.

During the late-night March accident, Mandel was riding in a vehicle owned by his 2012 U.S. Senate campaign, months after he'd lost his high-profile bid against Democrat Sherrod Brown.

Under federal campaign finance law, Senate campaign property can't be used for personal use or to campaign for a different office, such as treasurer.

Mandel's state treasurer campaign says it rented the vehicle from the federal campaign. The rental check cleared June 30, more than seven months after Mandel had lost the Senate race and almost four months after the accident, which totaled the vehicle.

Federal campaign rules generally require rental checks for transportation to be paid no more than 60 days after the travel takes place. Mandel's political team says both state and federal campaign finance lawyers were consulted on the rental arrangement.

As treasurer, Mandel has opted not to use state-owned transportation for official business on the premise that it saves taxpayers money. The practice, while legal, allows him to leave virtually no paper trail at his state office of his travel activity.

Campaign spokeswoman Rebecca Wasserstein said the practice is fiscally responsible.

"While many public officials use tax dollars to travel around the state, Treasurer Mandel is saving Ohioans thousands of dollars by not using a penny of taxpayer money," she said. "This is yet another example of Josh Mandel walking the walk as a fiscal conservative and leader with integrity."

Mandel faces a reelection campaign in 2014.