Prosecutors leading the Hunter Biden tax probe are investigating his purchase of a $142,000 plug-in hybrid sports car whose manufacturer defaulted on a massive Obama administration loan touted by his father, according to a report Monday.

Some of the testimony presented to a Delaware grand jury also appears to be intended to prevent the first son from mounting a defense based on his admittedly sordid history of drug and alcohol abuse, the Wall Street Journal said.

That testimony came from a former girlfriend, Zoe Kestan, 28, who last month testified about shacking up with Biden, 52, in swanky hotels in New York City and Los Angeles and making lavish purchases during 2018, a source familiar with the matter told The Post.

The car in question is a Fisker Karma, which was sold by the Fisker Automotive start-up company after it got $529 million in loan guarantees from the US Department of Energy to develop the Karma and convert an abandoned General Motors factory in the Biden family’s hometown of Wilmington, Del., for a planned line of family-oriented electric vehicles.

Biden’s father, President Biden, was vice president at the time and claimed that the green-energy initiative would create up to 2,000 jobs for assembly workers and serve “as a roadmap for all we can accomplish if everyone works together.”

Oscar-winning actor and environmental activist Leonardo DiCaprio was a Fisker investor who got the company’s first production Karma in 2011, and pop star Justin Bieber was given one for his 18th birthday by manager Scooter Braun on Ellen DeGeneres’ TV talk show in 2012.

U.S. Vice President Joseph Biden speaks in Wilmington, Delaware, U.S.
Then-Vice President Joe Biden said a loan for Fisker Karma to produce green-energy cars would create as many as 2,000 jobs for Wilmington, Delaware.
Bloomberg via Getty Images

Other investors in the company included some of Hunter Biden’s business partners, according to Breitbart News.

But Fisker went bankrupt in 2013 after receiving $192 million in federal loan payments, and the Department of Energy later admitted losing $139 million in taxpayer money on the deal — the most since the 2011 failure of solar panel maker Solyndra, which cost Americans $528 million.

Hunter Biden’s Karma was bought from a New Jersey dealership in 2014 with $142,300 provided by Kazakhstani banking oligarch Kenes “Kenges” Rakishev, the Journal said, citing bank statements it reviewed and a former Biden associate questioned by prosecutors.

Rakishev and former Kazakhstani Prime Minister Karim Massimov — who was fired as his country’s intelligence chief and arrested on treason charges in January — both posed for a photo with Hunter Biden and his dad that was apparently taken in Washington, DC’s Cafe Milano in 2015, when the elder Biden was vice president.

Hunter Biden eventually traded in his Fisker for a silver Porsche, his former associate told the Journal.

Prosecutors have been gathering evidence and presenting grand jury testimony about the paperwork behind the car’s purchase by Rosemont Seneca Bohai LLC, as well as payments the company received for Hunter Biden from the Ukrainian energy company Burisma Holdings and how he spent that money, the Journal said.

2013 Fisker Karma Eco Sport, at the 105th Annual Chicago Auto Show at McCormick Place in Chicago, Illinois.
Prosecutors leading the Hunter Biden tax probe are investigating his purchase of the expensive hybrid sports car.
Raymond Boyd/Getty Images

Rosemont Seneca Bohai was described in a bombshell report by Senate Republicans as an “apparent shell entity” owned by former Hunter Biden business partner Devon Archer, who last month was sentenced to a year and a day in prison for an unrelated bond fraud scheme that targeted the Oglala Sioux tribe of American Indians.

Hunter Biden was paid as much as $83,333 a month — or $1 million a year — to serve on the Burisma board of directors before his dad left office as vice president, when his salary was cut in half, according to emails contained on his infamous laptop computer, The Post has reported.

Zoe Kestan attends American Gods & Now Apocalypse Live Viewing Party At #TwitterHouse.
Zoe Kestan, Biden’s former girlfriend, testified in front of a grand jury in February.
Getty Images for Starz

Earlier this month, the New York Times said it had independently authenticated some of Hunter Biden’s emails, about a year and a half after The Post first revealed their existence — leading the Times to call them “unverified” and say they “prompted concerns about Russian disinformation” prior to Joe Biden’s 2020 presidential victory.

Prosecutors last month questioned at least one of Hunter Biden’s associates about his substance abuse, spending habits and state of mind in 2018, a source familiar with the matter told the Journal.

The move suggests they’re exploring whether it would help him defend himself against potential criminal charges so they could introduce it as evidence before his own lawyers if the case were to go to trial, the Journal said.

“It doesn’t necessarily mean an indictment is imminent, but it is indicative of trying to lock in testimony with an eye towards a potential trial someday,” former federal tax prosecutor Matt Mueller told the paper.

The Journal didn’t identify the witness, but a source familiar with the testimony told The Post it was Kestan, who testified before the grand jury for nearly five hours on Feb. 15, immediately after an appearance by the former stripper with whom Hunter Biden has an out-of-wedlock child.

Hunter Biden has paid about $1 million he owed in back taxes, but it’s unclear if he still has any debts to the IRS, the Journal said.

Last month, the Times said Hunter Biden paid off a significant tax liability that could make it harder for prosecutors to win a conviction or get a long sentence for tax offenses.

Neither Hunter Biden’s defense lawyer nor the Delaware US Attorney’s Office immediately returned requests for comment.

Kestan couldn’t be reached.