The Duke of Sussex's access to security when he visits the UK is under review, sources have told the BBC.

In May, Prince Harry lost a legal case to have his police protection reinstated when visiting the UK.

In a BBC interview after the ruling, he said it was not safe to bring his family back to the country of his birth because he could not guarantee their safety.

It is understood a Home Office review will now look at whether he should automatically receive full police protection on visits to the UK even though he is no longer a working member of the royal family.

Sources close to the prince say this level of security review is long overdue.

According to The Sun newspaper, the process for reassessing the duke's threat level is already under way and a decision is expected next month.

King Charles has only met the Duke and Duchess of Sussex's children once before.

He last saw his grandchildren, Archie and Lilibet, during the late Queen's Platinum Jubilee celebrations in 2022.

Prince Harry's security was downgraded after he stepped back from frontline royal duties in 2020 and moved to the US with the Duchess of Sussex.

In his legal challenge earlier this year, he contested the decision-making process used by a committee called the Protection of Royalty and Public Figures (Ravec), which authorises security for senior royals on behalf of the Home Office.

Ravec had concluded that because Prince Harry was going to be an infrequent visitor to the UK, his security needs would be assessed on a case by case basis.

But in doing so, the duke's legal team argued that Ravec did not properly re-assess the threats he faced when considering his situation in 2020.

His lawyers had argued that he had been "singled out" for "inferior treatment", but the court ruling upheld that there had been nothing unlawful about how the decision had been reached.

A senior judge ruled that Prince Harry's "sense of grievance" over how the decision to alter his security was reached did not amount to a basis for a successful appeal.

That decision meant the duke's security remained outside the automatic, high level of protection which is provided for senior royals.

Speaking to BBC News in California shortly afterwards, Prince Harry said he was "devastated" at losing his appeal.

He also said any prospect of a return to the UK for him and his family was "impossible" in light of the Court of Appeal ruling, adding: "I can't see a world in which I would bring my wife and children back to the UK at this point."

At the time, Buckingham Palace said: "All of these issues have been examined repeatedly and meticulously by the courts, with the same conclusion reached on each occasion."

A government spokesperson said: "The UK Government's protective security system is rigorous and proportionate.

"It is our long-standing policy not to provide detailed information on those arrangements, as doing so could compromise their integrity and affect individuals' security."