Prince Philip's will is to remain secret for at least 90 years

The judge - who is president of the Family Division of the High Court - has not seen or had the contents of the will disclosed to me other than the date of its ex ecution and the name of its ex ecutor, dec lared a private process can be held after the 90-year period has passed in order to determine if the documents should then be unsealed.

He wrote: "I have held that, because of the constitutional position of the Sovereign, it is appropriate to have a special practice in relation to royal wills.

"There is a need to enhance the protection afforded to truly private aspects of the lives of this limited group of individuals in order to maintain the dignity of the Sovereign and close members of her family."

The judge held a hearing with lawyers representing Philip's estate and the attorney general, who represented the public interest, in July, which was kept private because it would have generated "very significant publicity and conjecture" that would "defeat the purpose of the application."

He added: "I accepted the submission that, whilst there may be public curiosity as to the private arrangements that a member of the Royal Family may choose to make in their will, there is no true public interest in the public knowing this wholly private information."

It has been customary for almost 100 years for the wills of senior royals to remain sealed and in his position within the family courts, Andrew is said to be custodian of a safe which holds more than 30 sealed wills that belonged to deceased royal family members.