Britain's Prince Harry attends a rugby event at Buckingham Palace gardens in London
Prince Harry revealed in "Spare" that he used cocaine, magic mushrooms, and marijuana in the past. Reuters

Prince Harry may find himself having his U.S. visa revoked following revelations that he used illegal drugs during his wild partying days.

The Duke of Sussex admitted in his memoir "Spare" that he has tried magic mushrooms and marijuana, snorted cocaine when he was a teen, and used other drugs. "Of course, I had been taking cocaine at that time. At someone's house, during a hunting weekend, I was offered a line, and since then I had consumed some more," reads a passage from his book quoted by HuffPost.

Being candid about his past experience with illicit drugs may land him back in the U.K. Former federal prosecutor Neama Rahmani said that is "usually grounds for inadmissibility" telling Page Six, "That means Prince Harry's visa should have been denied or revoked because he admitted to using cocaine, mushrooms, and other drugs" and there is "no exception for royalty or recreational use."

However, Attorney James Leonard, who represented "The Real Housewives of New Jersey" alum Joe Giudice in his immigration case, does not agree with Rahmani. He does not see any risk to the 38-year-old's visa status unless there was a criminal charge involved.

He explained, "Absent any criminal charge related to drugs or alcohol or any finding by a judicial authority that Prince Harry is a habitual drug user, which he clearly is not, I don't see any issue with the disclosures in his memoir regarding recreational experimentation with drugs."

The New Jersey-based celebrity lawyer added that Prince Harry would have to give immigration officials valid reason to launch an investigation into his visa status, like criminal acts.

"You've got to give them something that would trigger it, and revealing it in a book, that you experimented with drugs when you were a young man, I don't think gets you there. Immigration is not going to do anything based on that. If he got arrested or if he got a DWI, then we're having a different conversation."

Immigration lawyer Sam Adair, an executive partner at Graham Adair, agrees with Leonard and said it is unlikely that the royal's "admissions will present a problem." He pointed out that had there "been a conviction, it would have likely been a significant issue in getting a visa."

"This isn't to say that drug use could not be a problem in the immigration process, but in this circumstance, it is unlikely that this would present an issue. It isn't clear to me what the duke's visa status is in the US, but breaking the law could be an issue in getting a visa renewed or for readmission to the US. But recreational drug use that has not been the subject of criminal scrutiny is unlikely to present an issue for someone's visa status," he explained.

Adair said that past recreational drug use is "not something that is likely to have been raised in a visa interview" so this was likely not an issue during Prince Harry's visa approval process. He reiterated that "drug use could be an issue if there had ever been an arrest, charge or conviction, but recreational use would not likely come up in the visa interview."

Leonard agreed and said that if Prince Harry had a criminal charge, then it could absolutely affect his U.S. visa status and "whether it gets renewed or terminated." But just to admit that you used illicit drugs in the past does not.

Rahmani argued that there is "no requirement that the person actually be convicted of a drug offense." He suggested that Prince Harry could "get a waiver" as proof he is "in remission" so he can avoid getting his U.S. visa revoked. This would require a doctor to forward medical records to immigration. But the duke has not disclosed whether or not he had to go to rehab for his past drug use.