The Obama administration stymied a sprawling investigation into the terror group Hezbollah — and its highly lucrative drug- trafficking networks — to protect the Iran nuclear deal, according to a bombshell report.

A team at the Drug Enforcement Administration had been working for almost a decade to bring down the Iran-backed militant organization’s sophisticated $1 billion-a-year drug ring, which laundered money and smuggled cocaine into the United States, Politico reported.

But the departments of Justice and Treasury repeatedly undermined agents’ efforts to arrest and prosecute key members of the criminal network — because the Obama White House feared upsetting Tehran ahead of the nuclear agreement, according to Politico.

Former Treasury official Katherine Bauer even admitted in little-noticed testimony to the House Committee on Foreign Affairs last February that “under the Obama administration . . . these [Hezbollah-related] investigations were tamped down for fear of rocking the boat with Iran and jeopardizing the nuclear deal.”

When the Iran agreement took effect in January 2016, the investigation — dubbed Project Cassandra — was effectively dismantled.

“This was a policy decision, it was a systematic decision,” said David Asher, an expert in illicit finance who helped found the project. “They serially ripped apart this entire effort that was very well supported and resourced, and it was done from the top down.”

The task force worked for eight years out of a top-secret facility in Virginia, with the help of 30 American and foreign security agencies, to unravel the global crime syndicate that was funding Hezbollah’s jihadist operations.

Politico also reported that late Venezuelan President Hugo Chavez was in cahoots with then-Iranian President Mahmoud Ahmadinejad and Hezbollah in cocaine trafficking and other activities meant to undermine US influence.

In 2007, Venezuela’s state-run Conviasa airline was ferrying drugs and cash from Caracas to Tehran via Syria each week, according to Politico.

DEA agents nicknamed the airline “Aeroterror” because the planes would come back carrying weapons, along with Hezbollah and Iranian operatives.

But the Obama administration never fought to have two major players in the scheme extradited to the United States to face charges when it had the opportunity, task force members charged.

Others the team sought to bring to justice were Abdallah Safieddine, Hezzbollah’s envoy to Tehran, and a shadowy operative nicknamed “Ghost,” whom it considered one of the biggest cocaine smugglers in the world.

“Hezbollah operates like the Gambino crime family on steroids, and [Safieddine] is its John Gotti,” ex-DEA agent Jack Kelly, who created the task force, told Politico. “Whatever Iran needs, Safieddine is in charge of getting it for them.”

Safieddine was ultimately linked to a massive drug-smuggling and money-laundering network allegedly led by Lebanese businessman Ayman Joumaa.

Agents discovered Joumaa had smuggled tons of cocaine into the States — then laundered $200 million a month by buying used cars from American dealers.

The cars were sent to Benin in West Africa, where satellite photos taken in 2015 showed rows upon rows of used cars in a lot.

But the Obama administration repeatedly thwarted efforts to prosecute Safieddine, Politico reported.

An Obama spokesman denied the operation was derailed for political reasons, noting several Hezbollah members were arrested.

Other administration officials suggested those involved were blind to the bigger picture.

“The world is a lot more complicated than viewed through the narrow lens of drug trafficking,” one official said. “So you’re not going to let CIA rule the roost, but you’re also certainly not going to let DEA do it either.”