Hunter Biden was suspected of smoking crack inside a strip club where he dropped “thousands of dollars” during multiple visits — at the same time he held a seat on the board of a controversial Ukrainian natural-gas company, The Post has learned.

The incident, which took place at Archibald’s Gentlemen’s Club in Washington, DC, late last year, represents the most recent alleged drug use by Biden, 49, who has acknowledged six stints in rehab for alcoholism and addiction that included a crack binge in 2016.

Workers at Archibald’s, located about three blocks north of the White House, said Biden was a regular there, with two bartenders and a security worker all instantly recognizing his photo and one worker identifying him by name.

Security worker Ranko Petrovic said Biden — the son of former Vice President Joe Biden, the Democratic front-runner to challenge President Trump next year — would routinely hole up in a VIP room and drink during his visits.

Although Petrovic said the club “had no issue with him,” former Archibald’s managing partner James Ritter said one occasion in late 2018 was marred by a “suspicion of drug use.”

“There was a smell of burning Styrofoam in the VIP room. We told him nothing illegal can go on here,” Ritter said.

“We didn’t see anything illegal. After he was spoken to, the smell stopped.”

“VIP employees suspected it was crack,” he added.

Hunter spent “thousands and thousands of dollars in the Archibald’s VIP rooms,” and paid his bills with “credit cards that didn’t have his name on it.”

The club generally required customers to use credit cards that matched official IDs, but “Hunter was a bit of an exception,” Ritter said.

“Whenever he was in town he came in for two days in a row, disappeared and come back a month later,” Ritter said.

Archibald’s current owner, Dan Harris, didn’t return an email seeking comment.

At the time of the incident, Hunter was a board member of the Ukrainian natural-gas company Burisma, which reportedly paid him as much as $50,000 a month.

That job lies at the heart of the ongoing impeachment inquiry against Trump, with Democrats alleging that the president withheld nearly $400 million in military aid to Ukraine in a bid to force an investigation into corruption allegations against Hunter and his dad.

Trump has denied any quid pro quo.

Hunter joined the Burisma board in April 2014 but declined the company’s offer to serve another term in May due to the controversy surrounding his membership, according to a July 1 profile by the New Yorker.

In an interview with ABC News last month, Hunter denied a suggestion that he wasn’t qualified because he “didn’t have any extensive knowledge about natural gas or Ukraine.”

“No, but I think I had as much knowledge as anybody else who was on the board — if not more,” he said.

Hunter — who’s currently embroiled in a paternity scandal with an Arkansas woman, Lunden Alexis Roberts — also conceded that being the son of the then-vice president “of course” played a role in his selection.

Hunter has never detailed the extent of the work he did for Burisma, although the New Yorker report said he attended board meetings and energy forums in Europe “once or twice a year.”

The magazine’s 11,000-word-plus profile was based on a series of warts-and-all interviews in which Hunter detailed a fall 2016 drug binge in Los Angeles, where he repeatedly bought crack at a homeless encampment while going without sleep for several days.

On Oct. 28, 2016, he checked into rehab at the Grace Grove Lifestyle Center in Sedona, Ariz., but left after only a week and headed to the nearby Mii Amo resort spa.

Hunter was joined there by former sister-in-law Hallie Biden — widow of his older brother, Delaware Attorney General Beau Biden, who died of brain cancer in May 2015 — and they launched an affair that lasted about a year, according to the New Yorker.

Hunter — whose first wife, Kathleen, obtained a divorce from amid his relationship with Hallie — re-married in May following a whirlwind, six-day romance with Melissa Cohen, 33.

In his ABC interview last month, Hunter said he’d “done estimable things and things I regret,” but was now “probably the best place I’ve ever been in my life.”

His personal lawyer and spokesman, George Mesires, didn’t return requests for comment.