The High Court on Tuesday heard arguments relating to whether letters between the Queen and Sir John Kerr, who dismissed prime minister Gough Whitlam, should be publicly released.

The so-called palace letters between Buckingham Palace and Sir John about the time of the 1975 dismissal have been deemed personal communications by the National Archives of Australia and the Federal Court.

Professor Jenny Hocking said at a time people wanted more transparency, keeping the letters secret only fuelled public distrust.

"The Queen could walk into the National Archives today and ask for those records and look at them and the Australian people can't," Prof Hocking told AAP outside court.

"That's just not an acceptable state of affairs for an independent nation."

Prof Hocking's legal team argues that despite being the personal letters of Sir John, they relate to the exercise and function of the governor-general's power.

And, as they are Commonwealth property, they should be subject to the same laws that see cabinet documents released after 20 years.

The Federal Court has previously ruled the letters - given to the national archives by Sir John - were personal, meaning they can't be released until 2027, and only then with the permission of the Queen.

The archives' legal team argues the records were created with the "strong conception" that their character was private, and they were received by the archives under those conditions.

The convention across Commonwealth nations was that communications between the Queen and her representatives were personal, private and not accessible by the executive.

Australian Associated Press