About 1,000 federal agents and local cops swarmed Los Angeles’ Fashion District on Wednesday and seized at least $65 million in cash in a massive crackdown on money laundering connected to Mexican drug cartels, authorities said.

The cops blocked off streets and raided about 70 different locations in the district — a 100-block section of downtown filled with retailers, designers and distributors that is the center of the West Coast apparel industry.

The crackdown targeted businesses suspected of taking part in the so-called “Black Market Peso Exchange” — a complex scheme in which the businesses help launder money for the violent drug cartels.

Nine suspects were busted — and the cash was seized from some of the LA businesses as well as from bank accounts around the world, the feds said.

“We have targeted money-laundering activities in the Fashion District based on a wealth of information that numerous businesses there are engaged in Black Market Peso Exchange schemes,” said federal prosecutor Robert Dugdale. “Los Angeles has become the epicenter of narco-dollar money laundering with couriers regularly bringing duffel bags and suitcases full of cash to many businesses.”

In one case, the Sinaloa Drug Cartel used a Fashion District business to accept and launder ransom payments to secure the release of a US drug dealer who was kidnapped by the narco-thugs, held hostage and tortured.

An indictment said the cartel ordered the dealer kidnapped after authorities in the US seized more than 100 kilograms of cocaine that he was supposed to sell, the feds said.

“The victim was held captive at a ranch in Sinaloa, where he was beaten, shot, electrocuted and waterboarded. The hostage was released after relatives paid $140,000 in ransom” through the Fashion District business, they said in a statement.

The peso brokers typically work with drug dealers who have US dollars in the States that they want to get to Mexico and convert to pesos.

The brokers find a business in Mexico that wants to buy goods from vendors in the US and needs American dollars to pay for them.

The peso broker arranges for the traffickers’ US dollars to be delivered to the US vendors to pay for the goods purchased by the Mexican business.

Once the goods are shipped to Mexico and sold for pesos, the pesos are then handed over to the peso broker, who gives them to the drug traffickers, the feds said.

“Today’s arrests and searches should send a message to international drug cartels that the FBI and our partners won’t tolerate the exploitation of American businesses for the purposes of illicit financial transactions that fund hostage-taking and the distribution of narcotics,” said Bill Lewis of LA’s FBI office.