Prince Harry has been embroiled in a debate about whether he disclosed his drug use to officials before moving to the U.S.

Harry's accounts of using psychedelic mushrooms, cocaine, and marijuana were detailed in his self-penned book, "Spare," released in January. Confessions of drug abuse can pose a significant challenge for non-Americans seeking entry into the country.

On Tuesday, the U.S. Department of Homeland Security communicated its decision to the Heritage Project, declining the request via an emailed letter, citing privacy regulations.

“Given that the records exist, this office doesn't see a public interest in the disclosure significant enough to override the subject’s privacy interests,” wrote DHS senior director Jimmy Wolfrey in the letter obtained by The Post.

Samuel Dewey, Heritage’s outside counsel, criticized the DHS response as demonstrating "an appalling lack of transparency by the Biden Administration" and pledged to continue the battle in court.

“The Department of Homeland Security’s efforts to obstruct the Heritage Foundation’s Freedom of Information request are unacceptable, and we will challenge their position,” Dewey asserted.

“We anticipated a fight at every stage of this case in federal court and will continue to push for transparency and accountability for the American people.”

The Heritage Foundation, a conservative research group, seeks to understand how Harry responded to questions in his U.S. visa application and how the DHS handled those responses before granting him entry.

Harry's visa status is unclear, but as the husband of a U.S. citizen, he could apply for permanent residency, and with his fame and wealth, he would qualify for various types of visas.

The deposed 38-year-old royal and his family relocated to the U.S. in February 2020 and currently reside in the tranquil, star-studded town of Montecito, California, approximately 100 miles from Los Angeles.

The foundation also requested expedited processing for the records and privacy protection exemptions due to the "immense public interest" in Prince Harry.

Mike Howell, director of the Heritage foundation’s Oversight Project, filed a Freedom Of Information Act request with DHS on March 8, 2023. The request sought records concerning the Duke of Sussex’s immigration application and related forms, as well as “all records” from several DHS and Customs and Border Protection databases.

Parts of the request were referred to CHP, U.S. Citizenship & Immigration Services, and the Office of Biometric Identity Management — all three rejected the requests.

The request has since devolved into a legal dispute between DHS and the Heritage Foundation, which sought judicial intervention.

Both sides appeared before District Judge Carl J. Nichols on June 6, who ruled that DHS must decide on the request by June 13.

Nichols will decide whether the Duke’s immigration records will be released.

After the June 6 hearing, Howell explained to reporters that he is seeking the records because “the everyday American is absolutely sick and tired of globalist elites lecturing us, looking down on us, dominating our cultural institutions — and no one proves that point more than Prince Harry.”

“In a high-profile case like this, when you're dealing with someone like Prince Harry, the American people deserve to know if their immigration laws are being applied fairly. And I think it’s absolutely ridiculous that we have to use taxpayer money to defend against these Freedom of Information requests and take it all the way to federal court.”