A man who claims he may be the son of the late Princess Margaret has won permission to continue his attempts to view her will.
Robert Brown claimed the princess gave him up at birth
Robert Brown, 52, an accountant from Jersey, had been denied permission to see the wills of both the Queen's sister and the Queen Mother.
The Appeal Court agreed his claims to be Margaret's son were unfounded and he had no private right to see the wills.
But it said he could test the principle that royal wills should be sealed.
Mr Brown believes he could be the illegitimate child of Princess Margaret, who died in 2002 aged 71, and Group Captain Peter Townsend, a former RAF pilot.
At an earlier hearing, his counsel, Geoffrey Robertson QC, said his client genuinely believed the wills could indicate that he was a beneficiary of certain bequests.
Family Division President Sir Mark Potter struck out the action, saying it was made "solely for the purpose of seeking to establish an imaginary and baseless claim".
Although he was born on 5 January 1955 in Nairobi, Kenya, his birth was not registered until 2 February and the birth certificate gives the date of 4 June 1955.
On Wednesday, Lord Justice Thorpe, Lord Justice Dyson and Mr Justice Holman, in the Court of Appeal, gave permission for an appeal to proceed.
Lord Justice Dyson said the earlier court decision was clearly correct, in that Mr Brown had no private right to view the wills.
He also noted that Mr Brown's counsel did not seek to support his claim to be Princess Margaret's child, which was "manifestly unfounded".
But, he added, it was at least arguable that he had the right to assert a general public interest in whether it was right for the wills to be sealed.
Mr Brown said the ruling had exceeded his expectations.
His solicitor, Amber Melville-Brown, said: "We are absolutely delighted with such an emphatic ruling. A door we thought had been shut in our faces has been opened."
Since 1911, the wills of senior members of the Royal Family have been officially sealed and not open to public inspection.