The joint FBI-Miami police corruption investigation was launched a year ago when the Liberty City sports gambling ring was broken up.

Last month, Miami officer Nathaniel Dauphin pleaded guilty to an extortion charge for providing protection for the illegal betting business.

Dauphin, 41, admitted he received between $4,000 and $5,000 from the owner of the illegal business from November 2010 until March of last year. Unbeknownst to him, Miami-Dade police detectives had the place under surveillance, witnessing Dauphin as he took money from the owner of the Player’s Choice, 6301 NW Sixth Ave., a barber shop that fronted for the illicit sports-betting business.

Investigators flipped Dauphin, who wore a wire and targeted other city cops, including Harold James, 29, an eight-year police veteran who resigned in November. He pleaded guilty last month to two extortion charges for protecting the Liberty City check-cashing business.

Also ensnared in that probe: Frederick.

But among the latest corruption cases, Bazile’s stands out for its sheer size, authorities say.

According to a criminal complaint, FBI and Miami police internal affairs detectives installed a tracking device on Bazile’s work-issued laptop in the past year after they uncovered that he had run more than 1,000 “suspicious” searches of people’s names in the Florida Department of Highway Safety and Motor Vehicles database.

Investigators found that Bazile supplied some of those names, with dates of birth and Social Security numbers, to his step-brother Jean Baptiste Charles, to submit false tax returns to the Internal Revenue Service. Charles pleaded guilty last month and faces sentencing in April.

Investigators soon discovered that Bazile also obtained personal information for hundreds of women with the same last names, such as Rogers, Gonzalez, Martinez, Lopez and Sanders, who were between 57 and 61, according to the criminal complaint.

Bazile filed nearly identical tax returns — with fabricated income information — in their names, claiming that each had earned unemployment compensation of $6,500, the complaint said. He sought refunds up to $1,700 each.

Investigators also obtained numerous ATM photos of Bazile last summer as he withdrew thousands of dollars on debit cards loaded with the refunds, which were issued by the IRS.

When investigators confronted Bazile in October, he signed a written confession, admitting he used the state database, withdrew money from the ATM machines on the debit cards, and made between $130,000 and $140,000 in 2011-2012 from the “scheme.”

Investigators searched his home and found more debit cards, as well as ledgers with hundreds of people’s personal data.

Acting FBI special agent in charge William J. Maddalena said police officers such as Bazile and his colleague, Frederick, “have a great responsibility and must be held to a higher standard.”

He added that the FBI’s Miami-area corruption task force was established in 2009 to “ensure these high standards of integrity are met and maintained.”