Prince Harry's bitter legal battle with the Home Office has so far cost the UK taxpayer £300,000.
The Duke of Sussex launched a Judicial Review in the High Court after his armed security was cut when he stepped down as a working member of the Royal Family.
Prince Harry branded the decision "unfair" and offered to pay for police protection himself.
However, the Duke of Sussex was told that police were not "guns for hire" and his offer was rejected.
The Duke of Sussex stepped down as a working member of the Royal Family
Netflix
On Sunday evening, a source told the Sun: "He claims not to want taxpayers to foot the bill for his guards — but they are being made to pay hundreds of thousands for his court case."
Prince Harry is given armed protection for official events or when he resides at Frogmore Cottage.
The Duke of Sussex's Home Office case could go before the High Court in early April but it is unclear whether it will be resolved before King Charles's Coronation in May 2023.
It comes as Meghan Markle and Prince Harry's lawyers are "casting an eye" over South Park's latest series after the show launched a number of attacks on the couple.
South Park has taken multiple shots at Meghan Markle and Prince Harry mocking their claims they want privacy despite signing lucrative deals with Netflix and Spotify to publish content about their lives.
Prince Harry's autobiography Spare has been ridiculed with South Park referring to it as "Waaagh".
The series has also branded the couple "dumb" and "stupid".
Royal commentator Neil Sean has stated the couple's legal team is now watching the series closely for any more attacks.
South Park have fired multiple digs at Meghan and Harry in their new series
Dominic Lipinski
Sean said: "According to sources close to the ex-royals, it appears that, like so many things with Meghan and Harry, this may have legal ramifications attached.
"Their legal team are casting an eye over the episode to see what is wrong, and what could be turned into something more sinister."
However, Fox News have stated it has not yet been confirmed whether legal action will be taken or not.