Rivera already faces a federal investigation tied to his personal and campaign finances, which came under scrutiny due to a secret $500,000 dog-track payment in 2008. He narrowly avoided 52 state charges as part of an investigation that showed a campaign ally converted $190,000 in cash that essentially disappeared in 2010

It’s unclear how Sternad afforded any mailers used in his race, let alone the large sums of cash.

But his campaign enabled him to win nearly 11 percent of the vote, finishing third behind Garcia and Gloria Romero Roses, whose campaign could have been helped the most by Sternad’s effort.

Married to an unemployed wife, Sternad has five children and pulls in about $30,000 in income from part-time hotel work, records show. Despite having only modest investments, Sternad was able to loan himself nearly $11,000 for his campaign.

After spending $10,440 on the state fee to qualify for the ballot, he spent everything else on phones, a few campaign signs and postage, his pre-primary campaign-finance reports showed.

Total cash on hand: $120.97 on July 25.

After that date, FEC rules require any contribution exceeding $1,000 to be reported within two days. Even if Sternad loaned himself the money, he would have to report it within two days in the final days of the primary.

The FEC said Sternad filed no 48-hour reports.

Sternad’s reports on the FEC website show no expenditures for Rapid Mail, Campaign Data, Expert Printing or his campaign consultant, Ana Alliegro, a Rivera friend who has refused to comment and couldn’t be reached Wednesday.

Alliegro was also a paid consultant for Sternad’s attorney, Yabor, in his failed bid for county judge Aug. 14.

Federal officials usually consider campaign-finance violations civil matters — unless a candidate or campaign is knowingly and willfully violating filing false reports or failing to disclose contributions.

For this primary, Sternad was limited to receiving $2,500 contributions per individual. Contributors are banned from giving more than $100 in cash.

Sternad’s attorney, Yabor, claimed Sternad filed updated campaign-finance reports Friday with the FEC, where a spokesperson said the documents had not been received on the day Yabor indicated.

Yabor refused to provide the documents to The Herald.

But even if the documents were filed late, it might not matter to federal authorities, said Kenneth Gross, a top Washington-based election-law lawyer expert who’s not involved with the case.

“When it comes to reporting, there’s no putting the toothpaste back in the tube,’ Gross said.

“You can’t just automatically say ‘whoopsie, sorry, there was a mistake, let me fix this.’ The law does not provide for your violation to be vitiated if you correct the problem after the fact.”

Miami Herald reporter Patricia Mazzei contributed to this report.