The Duke of Sussex's US visa application should remain private despite him admitting taking drugs in his memoir, a judge has ruled.

Prince Harry wrote of using marijuana, cocaine and psychedelic mushrooms in his memoir Spare, which was released in January 2023.

A lawsuit, from the conservative Heritage Foundation, sought to compel the government to release the records to show whether drug use was disclosed.

But US judge Carl Nichols ruled on Monday that "the public does not have a strong interest in disclosure of the duke's immigration records".

"Like any foreign national, the duke has a legitimate privacy interest in his immigration status," he added.

Prince Harry moved to the US in January 2020 after announcing that he and his wife, Meghan Markle, would step back from royal duties.

In a lawsuit last year, the prominent Washington DC-based think tank argued that "widespread and continuous" media coverage of Prince Harry's admitted drug use called into question whether the government properly vetted the duke and followed proper procedures when it admitted him into the country.

Application forms for US visas specifically ask about current and past drug use.

Drug use can lead to non-immigrant and immigrant visa applications being rejected, although immigration officers have discretion to make a final decision based on a number of factors.

The Heritage Foundation's lawsuit argued that US law "generally renders such a person inadmissible for entry" to the country.

In his memoir, the duke said cocaine "didn't do anything for me", adding: "Marijuana is different, that actually really did help me."

But Judge Nichols said the public's interest in disclosure of Prince Harry's immigration records is "outweighed by the duke's privacy interest".