The Duke of Sussex’s private security team recognised the woman immediately, as she is listed on a register of fixated individuals maintained by a private intelligence company working for the estranged royal.

Despite being alerted, court security staff were unable to intervene.

A source close to the Duke told The Telegraph: “There is nothing they could do; they are not the police. It’s a public building, and she has a right to be there.”

The source added: “He is obviously always worried about his security situation; it’s not ideal.”

A Pattern of Concerning Encounters

The incident comes as the Home Office continues a security threat review that was launched in December.

The woman, who is believed to have mental health difficulties, has previously appeared close to the Duke on multiple occasions.

She is said to have followed Harry to Nigeria and last September breached security at a central London hotel, where she gained access to a secure area during the WellChild Awards ceremony.

Just two days later, security sources confirmed she was again seen near the Duke at the Centre for Blast Injury Studies in west London.

Ongoing Threat During High Court Case

These repeated encounters highlight the persistent risks facing Harry, who attended the High Court for four days at the start of his £38million privacy trial.

He also gave evidence on the stand for just over two hours on Wednesday.

The current security review represents a notable change in government stance, coming despite Harry’s earlier defeat in a legal challenge against the Home Office over his right to automatic, state-funded protection.

After losing that appeal, the Duke wrote directly to Home Secretary Shabana Mahmood, hoping for a different approach from that of her predecessor, Yvette Cooper.

Around two months later, the Risk Management Board agreed to carry out a full assessment, with its findings due to be passed to the Royal and VIP Executive Committee, known as Ravec.

Risk Level and Expert Warnings

Harry’s last full threat assessment was carried out in 2019 while he was still a working royal, when assessors placed him in the highest possible risk category, level seven out of seven.

Neil Basu, the former head of the UK’s Counter Terrorism unit who sat on Ravec between 2018 and 2021, believes the Duke has been left exposed without armed protection.

He said repeated encounters with a stalker “must be incredibly anxiety-inducing”.

“There are clearly people with fixations, and you can never fully know where that fixation will lead until you’ve assessed that person’s state of mind – it might be declarations of undying love and sending roses, or it might be wanting to cause harm,” he said.

Mr Basu described the Home Office’s decision to conduct a review as “incredibly positive”, adding that he could not see how Harry’s risk level would have reduced since 2019.

“As one of the most recognisable men on the planet, his threat and risk will be, in my view, the same as it was in 2019. It may even have increased because of the publicity around him,” he said.