When DeCarolis returned 12 days later, the Barreiro signs had been replaced by MCM signs, DeCarolis wrote in his statement.

DeCarolis submitted photographs documenting the change. A private investigator hired by FHP corroborated DeCarolis’s account that the office was being used as a campaign headquarters before Oct. 23, according to city records.

Barreiro said he is to blame for taking down the MCM signs, and that there was someone from MCM working alongside him in the office the entire time he rented the property.

“I, unfortunately, took the sign down,” he said.

After FHP filed a bid protest, Miami Chief Procurement Officer Kenneth Robertson launched his own investigation. Robertson discovered that while MCM’s top executives own the building on Southwest First Street, the company had not paid the tax required to run a business at that location. It had, however, paid the business tax on a South Miami property.

Robertson rescinded the recommendation to go with MCM on Dec. 5.

MCM is protesting the move. The company did not return calls from The Miami Herald.

“MCM is a local contractor that started in the city of Miami and has maintained a continuous presence in this city for nearly 30 years,” the company’s attorney, J. Alfredo Armas, wrote in a letter to the procurement office.

Armas contends that MCM had paid for the business license, but that it didn’t show up in county records.

County records show the property belongs to a company known as 1429 LLC, which is owned by the Munilla family. The two-story home has four bedrooms and two bathrooms, and was recently assessed at $346,458.

Barreiro reported paying his rent via checks written to another Munilla company, 1401 Professional Center LLC, from June 15 through Nov. 15, Miami-Dade County campaign disclosure records show. He voted to award the Metrorail contract on May 7 and Nov. 20.

The commissioner said he only rented the first floor, which has less than 1,000 square feet. He said he scouted several locations along the street — the same street where his family owns property — and was told repeatedly there was nothing available. He said he finally approached the Munillas and was told the office he rented was the only space available.

“Look, I buy my water from [Miami-Dade] Water and Sewer. Is that a conflict?” Barreiro asked. “The rationale of the conflict issue, this is not me, it’s a campaign, so I don’t see it. It’s not my contract, per se.”

University of Miami law professor Tony Alfieri, who also directs the school’s Center of Ethics and Public Service, said Barreiro’s votes to give MCM business raise questions.

“A county commissioner, like other citizens, has the freedom to associate, and that’s fine,” Alfieri said. “But in this case, given both his personal and business associations, and the campaign contributions, not only does he have the duty to disclose, but he has the duty to recuse.”

Meanwhile, Robertson, the Miami procurement director, is working on a final report to give to the Miami City Commission, he said. Commissioners will likely take up the issue at their next meeting on Jan. 10.

Commissioners want to move quickly so work on the Museum Park promenade project can begin.

“The museums will open and the park won’t be done,” Commission Vice Chairman Marc Sarnoff said.