As Miami-Dade County’s real estate market went bust, vocational school maverick Ernesto A. Perez began looking south to scoop up properties in Homestead’s depressed downtown to open a new link in his chain of for-profit colleges.

Perez would soon discover two eager allies: Mayor Steven Bateman and his wife, Donna, a real estate agent.

Now, the mayor is under criminal investigation for allegedly pushing Perez’s project to build a university on city-owned land, for which he lobbied feverishly behind the scenes while publicly maintaining a discreet distance. Public records suggest Bateman badgered Homestead government staffers and manipulated the process in a bid to help Perez purchase the municipal properties in the historic-but-lifeless downtown area at a fraction of the appraised value — while steering Perez’s real estate transaction to his wife.

In the end, Perez, chief executive officer of Dade Medical College, won a bargain-basement option to buy 3.5 acres in the downtown area; Bateman’s wife got a lucrative business referral; and the mayor received at least 15 $500 contributions to his 2011 mayoral campaign from Perez and his associates. He won the election.

As for Homestead taxpayers, they stand to receive less than 40 cents on the dollar from the land transaction.

Miami-Dade State Attorney Katherine Fernández Rundle said Friday that her office is investigating several allegations stemming from Homestead, including those about the mayor and his role on the Community Redevelopment Agency’s board, which approved the property sale to Perez’s business.

“We have been receiving numerous complaints from divergent groups in Homestead. We have been subpoenaing records and interviewing witnesses for the past several months,” Fernández Rundle said.

The Miami-Dade Commission on Ethics and Public Trust, which does civil investigations, has also sought public records from the city of Homestead regarding the same probe.

The land in question has mostly been vacant since 1992, when Hurricane Andrew destroyed many homes in the area west of Krome Avenue, downtown’s historic main street. Council members, who sit on the CRA’s board along with the mayor, enthusiastically embraced Perez’s vision for a four-year university, retail stores and parking garage on the vacant land. He had already opened a Dade Medical College facility in a leased corner building on Krome, and acquired two other nearby properties for a nursing school and medical diagnostic training.

But now the CRA board’s hopes of reinvigorating the area have been overshadowed by the state attorney’s investigation, which is focusing on the mayor’s alleged misuse of his public position for personal gain and his lack of disclosure about his wife’s real estate interests with Perez and Dade Medical. The wife represented Perez and the college in their purchases of other downtown properties, including a defunct five & dime store.

After the city’s land sale to Dade Medical was given preliminary approval, Bateman traveled last year with Perez to Tallahassee on a jet leased by Dade Medical to lobby the governor on major road improvements to the Krome Avenue area, near Perez’s proposed university.

Bateman served as chairman of the city’s Community Redevelopment Agency board in late 2011 when it approved an option agreement to sell the CRA’s property to Dade Medical for $328,000 — roughly one-third of its value as determined by an independent real estate appraisal. The board voted unanimously to finance 80 percent of the purchase price, at a 5 percent rate over 15 years, with a balloon payment after five years. Dade Medical had to put down 20 percent in cash and pay the commission to its real estate broker, who works with the mayor’s wife.