Prince Harry's recent allegations regarding a payout he and his brother Prince William received over phone hacking claims have caused tension between the siblings, according to royal expert Camilla Tominey. She discussed the issue on the Australian TV show Today, describing Harry's statement as "another bombshell" that could further strain the relationship between the two brothers.

On Tuesday, during a three-day legal hearing in London, court documents submitted by Harry's lawyers claimed that William reached a settlement with News Group Newspapers (NGN), publisher of The Sun and the defunct News Of The World, over alleged phone hacking. Prince Harry is currently suing NGN for alleged unlawful information gathering by its publications.

NGN has requested Mr. Justice Fancourt to dismiss both claims, asserting that they were filed too late. Tominey noted on the TV show that Harry's implication has "ruffled feathers behind palace gates."

In response to NGN's strike-out application, Harry's lawyers claimed that there had been a "secret agreement" between the royal family and NGN, which was communicated to Harry in 2012. David Sherborne, representing Harry, stated that the late Queen was involved in the "discussions and authorization" of this alleged agreement, which stipulated that the royal family would not pursue claims against NGN until after the litigation over phone hacking was concluded.

Sherborne argued that this agreement "meant that the claimant could not bring a claim against NGN for phone hacking at that time." He further stated that it was "agreed directly between these parties, as opposed to their lawyers ... that at the conclusion of the Mobile Telephone Voicemail Interception Litigation (MTVIL) News would admit or settle such a claim with an apology."

Sherborne also revealed that Prince William had "recently settled his claim against NGN behind the scenes." Kensington Palace has declined to comment on behalf of Prince William.

In a witness statement prepared for the hearing, Harry recalled being told by someone from the royal institution that neither he nor his brother could bring a claim against NGN for phone hacking at that time, citing the "secret agreement."

However, Anthony Hudson KC, representing NGN, denied the existence of such an agreement, adding that while discussions between the Palace and NGN took place, they did not suggest that NGN would waive its right to bring a limitation defense against any claims by royal family members.

The hearing is set to last three days, and the judge will determine if the claims will proceed to trial, scheduled for January next year.