Prince Harry urged to release details of his US visa application over …

Prince Harry has been urged to be 'totally transparent' and release details of his US visa application or risk becoming a 'political pawn' over his past drug use.

US immigration authorities have until April 12 to respond to a Freedom of Information (FoI) request filed by a leading American think-tank which is seeking to determine how the Duke of Sussex was allowed to enter the States after openly admitting using a variety of substances in the past, including marijuana, cocaine and magic mushrooms.

Under US law, anyone applying for a visa to live and work in America has to tick a box to answer 'yes' or 'no' to the question: "Are you or have you ever been a drug abuser or addict?"

In his controversial memoir Spare and in a 'therapy session' with toxic trauma expert Dr Gabor Mate to promote his book last month, Harry admitted using psychedelic drugs.

They included the hallucinogenic Amazonian plant ayahuasca, whose effect he described as 'the cleaning of the windshield, the removal of life's filters'.

But under US law, an admission of drug use usually results in a person being denied entry to the States, as happened in the case of chef Nigella Lawson and the late singer Amy Winehouse.

The issue of immigration is expected to become one of the main focuses of the 2024 presidential election, with Republicans attacking President Joe Biden for his lax border controls.

And there are fears that Harry's friendships with prominent Democratic Party figures such as former president Barack Obama and major Democratic donors including Oprah Winfrey and Tyler Perry could see him become an 'unwitting pawn in a highly political game'.

Last night, in an exclusive interview with The Mail on Sunday, senior lawyer Samuel Dewey at conservative think-tank the Heritage Foundation, which has filed a 127-page FoI request to see the Duke's application, said: "It is in the public interest to know how Prince Harry answered the drug question.

"If he has been honest and open about his drug use, and there is no reason to believe he has not been, it could well be that he ticked the "yes" box, in which case he would need a waiver to be granted a visa to be admitted into the States.

"That means he would have had to be interviewed in person and someone would have had to grant him a waiver.

"We are simply asking who granted that waiver."

There is a history of authorities releasing immigration documents about public figures.

The US Citizenship and Immigration Services website has an electronic reading room which contains the immigration files of people such as Shyamala Gopalan Harris, mother of US Vice-President Kamala Harris, and George Michael and John Lennon.

Other celebrities whose files are open to the public include Canadian-born Superman actress Margot Kidder and British actress Lynn Redgrave.

Mr Dewey added: "An admission of drug use doesn't automatically ban you forever.

"There is a waiver process and a lot of people get a waiver on a caseby- case basis. If Prince Harry was given a waiver, who authorised it? Was the correct protocol followed?

It's something the American people deserve to know."

Often a ban is overturned after an in-person interview at a US consulate or official immigration office, where a waiver can be issued.

In 2014, Ms Lawson was prevented from entering the US after admitting during a court case to taking cocaine, even though she told a judge:

"I have never been a drug addict.

I've never been a habitual user."

She was later granted a visa after being interviewed at the US Embassy in London, while Ms Winehouse was twice refused entry because of her drug use.

Mr Dewey said: "There is no suggestion Prince Harry did anything wrong and, if he was granted a waiver, he may not be aware of any political strings that may have been pulled, if indeed they were.

But there is a danger he could become an unwitting pawn in an issue which has become a political hot potato."