For Bal Harbour police, it was a whirlwind: cops jetting to Las Vegas, Chicago, Phoenix, Los Angeles — with the goal of seizing millions from criminals.

Two flew on first-class flights while two others went business class to California, where they stayed in the wine country of Temecula Valley.

In just one month, the village’s police helped reel in $3 million — and by the end of the year, they took more dollars from drug dealers than any police force in Florida.

While small police departments rarely venture beyond their borders, Bal Harbour’s force has become a massive cash generator, infiltrating drug organizations across the country with no connection to the coastal village.

Armed with a team of snitches and undercover cops, the vice unit makes few arrests, but seizes a fortune in cash every year.

Now, the special unit is under federal investigation for its handling of millions in seized dollars, including hundreds of thousands paid to snitches, questionable expenses and missing financial records.

In a rare move, agents have frozen millions that Bal Harbour helped confiscate under a program that allows police to seize the riches of criminals — and keep a cut of the proceeds.

For the past year, the village has been forced to turn over reams of records in a grueling audit that’s now under review by U.S. Department of Justice prosecutors.

Bal Harbour Police Chief Thomas Hunker, who was subpoenaed in March, said his unit has never broken the law.

“Since 1994, I’ve had not one incident where anything is missing,” said Hunker, 61, who has been chief since 2003. “We have a standard operating procedure and a policy and sign-in logs that we have to maintain control.”

Hunker, an unsuccessful candidate for the Miami Beach chief job this year, blamed much of the probe on jealousy by federal agents.

“Sometimes we give them cases. Sometimes we don’t. If we don’t give them a big case, and we get a big hit, they get pissed. It’s competition.”

But even before the investigation, the village’s forfeiture fund came under scrutiny in May by its own auditors, who found questionable expenses, poor accounting and a lack of oversight.

Al Treppeda, the village manager and former police chief, did not return a phone call on Friday, referring all questions to the police.

Now, federal agents are looking at the flow of money into the town — including plainclothes cops toting bags stuffed with cash on airliners and later counting it in a police trailer.

For years, the department of 27 officers, serving a village of 2,574 people, has run its forfeiture program like an ATM machine, tapping into a network of informants who led police to the cash.

And for years, the money rained on Bal Harbour: $100,000 for a 35-foot boat powered by three Mercury outboards, $108,000 for a mobile command truck equipped with satellite and flat-screen TVs, $25,463 for next generation Taser X-2s.

There was $7,000 for a police chiefs’ banquet, $45,839 for a Chevy Tahoe, $26,473 for Apple computers, $15,000 for a laser virtual firing range and $21,000 for an anti-drug beach bash.

The biggest pay — $624,558 — to snitches over the past four years.

Not until the government temporarily banned the village early this year from sharing in forfeiture dollars did the flow of money stop.