See Late Update below

A financial interest held by Mitt Romney’s son in a voting machine company whose systems are being used in Ohio threatens public confidence in the election’s integrity, according to Jennifer Brunner, the state’s former top elections official.

“It doesn’t look good for a presidential candidate’s son to be an investor in a voting machine company,” Brunner told msnbc.com. “That has to do with public trust in the process.”

Hart Intercivic supplies voting machines that will be used in Hamilton County, Ohio, one of the state’s most populous counties. In 2008, Barack Obama won the county with 209,000 votes—his third highest vote total among all Ohio’s 88 counties.

H.I.G. Capital, a large investment fund, is a “significant investor” in Hart Intercivic, according to an announcement put out last year by Hart. And H.I.G., in turn, is one of the largest partners, with nearly $10 billion of equity capital, of Solamere Capital, the investment fund founded and run by Tagg Romney (pictured), Mitt’s eldest son, The Nation recently reported*.

Mitt Romney seeded the firm with a $10 million investment, offered strategic advice, and was the featured speaker at its first investor conference in 2010, The Nation reported.

Brunner, a Democrat, served as Ohio’s Secretary of state from 2007 until 2011. In 2007, a test conducted by her office found voting systems run by Hart Intercivic and four other companies had critical flaws that could allow them to be corrupted.

A report Saturday on Forbes.com raised concerns about that history, given Hart Intercivic’s ties to Solamere. It also noted that two Hart directors have made contributions to the Romney campaign. (In the case of one, Jeff Bohl, the donations were made to Romney’s last presidential campaign in 2007 and 2008, before Bohl became a Hart director.)

Brunner, however, told msnbc.com that the threat of a deliberate, politically motivated effort to corrupt the system’s results is very low. “Because we did the study, we were able to put into place a very comprehensive set of procedures to ensure that everything works as it should,” she said, adding that the software is now kept in a “secure location without any kind of random access.”

In a statement to msnbc.com, a company spokesperson said: “Hart InterCivic has a long track record of supporting a fair and open democratic process. Any suggestions that the Company might try to influence the outcome of election results are unfounded.”

Nonetheless, Brunner said, for a close family member of a presidential candidate to have a stake in a company charged with administering election results in a key swing state raises at least the appearance of a conflict.

“I think you’d be right to call out Romney and his son for having a financial interest in this company,” she said. “It doesn’t look good.”

*This sentence has been corrected from an earlier version.

Late Update, 10/22 9:56 am: A Solamere spokesman said in a statement, referring to Hart Intercivic: “Neither Solamere nor its principals have any ownership in the company or in the fund that owns the company.”