Prince Harry's controversial US visa files have been delayed until after King Charles's state visit to America.

US officials have quietly pushed back a planned release of his visa documents until after his father's high-stakes trip to Washington.

Campaigners have been asking for years to view the files, to see if Harry lied on his application for a US visa about whether he had ever taken drugs.

Since moving to America, the Duke of Sussex has admitted in his memoir Spare that he previously used cocaine and marijuana.

US think-tank the Heritage Foundation and researcher Mike Howell brought a freedom of information case and sued the US State Department to force it to comply with the request.

Hundreds of official documents relating to the case have been identified. 

In a new court filing in Washington DC made public this week, officials admitted they missed a March target to hand over documents.

They said the next update in the case had been postponed until at least June 12 - long after the royal trip has safely concluded. The court filing makes no mention of the state visit, but the delay timing will have the effect of avoiding any embarrassment to Harry's father.

 King Charles and Queen Camilla are scheduled to be feted at a glittering state banquet hosted by President Trump at the White House in late April. The state visit is to mark the 250th anniversary of American independence. Charles will be presented as a symbol of the special relationship during a trip already considered a diplomatic minefield.

President Trump recently lashed out at Prime Minister Keir Starmer for refusing to support Operation Epic Fury, adding tension to the political environment ahead of the royal visit. Any dispute over the right of his younger son to live in his California mansion could potentially risk casting a shadow over the trip for both governments.

The legal fight centres on the admissions Harry made in Spare, and in subsequent interviews detailing his past use of cocaine, cannabis and magic mushrooms.

Under standard US immigration rules, such admissions of drug use would ordinarily raise red flags. Visa applicants are asked about any past drug use, and admissions can potentially bar ordinary applicants from entering the country or lead to their deportation.

Lawyers representing the Heritage Foundation argue there is a clear public interest in seeing how the administrations of Joe Biden and now Donald Trump handled the case. 

US officials insist the delays are purely bureaucratic, citing the sheer volume of material and the need to consult across multiple government offices before releasing any documents.

The court filing dated April 13 states: 'The Department previously anticipated being able to make an initial interim production in this case in March, and commence rolling productions as available hereafter. The Department, however, is still processing a potential first tranche of records and will produce them as soon as possible.'

The 'status report' reveals that the State Department has identified 307 separate records spanning 2,487 pages that could be relevant to the Duke.

He is formally named in the civil action as Henry Charles Albert David also known as the Duke of Sussex.

Officials said the visa-handling Bureau of Consular Affairs initially flagged 517 potentially relevant documents. The Office of the Secretary identified 217 additional records, while the Office of the Legal Adviser located 271 potentially 'responsive' documents. Two additional records were found on the Deputy Secretary of State's desk.

The legal battle has dragged on for nearly three years since the Heritage Foundation first went to court Harry quit royal duties in 2020 and has maintained a frosty relationship with his father ever since.

The Trump administration has previously said that claims Prince Harry received special treatment when he emigrated to the US were false. It said Harry's application had followed all the 'applicable rules and regulations'. 

Prince Harry's spokesman was approached for comment.