Two months before the Miami-Dade County mayoral elections, the leading candidates are raising questions about the finances behind each other’s electioneering communication organizations, or ECOs.

On Monday, county Mayor Carlos Gimenez said he didn’t know that a foreign national had illegally given $10,000 late last year to his ECO, Common Sense Now, and was now returning the money.

Meanwhile, Joe Martinez’s campaign manager defended the existence of a corporation that was set up to take donations from people who do business with the county but don’t want their names to appear as contributors. The corporation then gave $100,000 to the ECO that supports Martinez.

El Nuevo Herald reviewed the most recent campaign reports for both candidates’ ECOs, which under state law are allowed to buy political advertisements that support or criticize a candidate without expressly advocating for their election or defeat.

Common Sense Now, which supports Gimenez’s reelection campaign, had about $645,000 in its coffers as of March 31, according to the most recent financial reports. Get It Done, which supports Martinez, had about $260,000 at the time.

Gimenez said he refunded $10,000 to Fernando Fraiz-Trapote on Monday after learning the Venezuelan businessman isn’t a U.S. citizen or permanent resident.

“It’s one of those things that fall through the cracks sometimes during campaigns,” he said, adding that he was glad to be able to return the money before his ECO closed its books.

Fraiz-Trapote’s wife is a U.S. permanent resident who can legally make her own $10,000 contribution to Common Sense Now, Gimenez said. He doesn’t know if that’s her plan.

The couple lives in a $4.5 million home in the gated Cocoplum community in Coral Gables. The family declined to allow reporters past the gate and didn’t respond to phone messages. Fraiz-Trapote owns several companies in Venezuela, including the television channel LaTele and the advertising company Vepaco.

Martinez’s campaign manager, Sasha Tirador, attacked Gimenez for having accepted the contribution. “If you don’t have the capacity to be on top of something like a foreign national contribution to one of your PACs” — political action committees — “then I don’t think you’re qualified to be mayor,” she said.

Then Tirador tried to explain why Martinez’s campaign treasurer and the director of his ECO had created a not-for-profit corporation called Citizens for a Better Miami-Dade County Inc. last year. As a corporation, Citizens doesn’t have to disclose its finances as long as the majority of its work isn’t about making political contributions.

Citizens takes donations from those who want to make a contribution to Get It Done, the ECO, but are afraid of doing so publicly, Tirador said. Its donation in March of $100,000 to Get It Done accounted for more than a third of all contributions to the ECO during that reporting period.

“It’s not because Joe’s campaign has anything to hide,” Tirador said. “It’s to protect those businessmen and women who want to contribute to Joe’s campaign but are afraid that Gimenez will take revenge on them if he’s reelected.”

She added: “It’s legal.”

The explanation didn’t sit well with Gimenez.

“That’s the most ridiculous thing I’ve ever heard in my life,” he said. “This flies in the face of the principles of transparency in elections. It’s probably legal, but I find it hypocritical.”

Martinez didn’t respond to multiple requests for comment. Neither did the two men who are registered on Citizens’ board of directors.

Pedro Diaz, who also chairs Get It Done and is the son of a former district office coordinator for Martinez, didn’t respond to messages left in his office, home and on his phone.

Federico Garcia, who is also treasurer of the Martinez campaign, declined to speak with El Nuevo Herald at his office on Friday, explaining that he was busy and needed to see all questions in writing. Subsequently, an El Nuevo Herald reporter sent him a an email with questions. On Monday, Garcia said through his receptionist that he needed at least a week to respond.