Australia's prime minister Julia Gillard insisted she did not break royal protocol by deciding not to curtsy to the Queen.
When the politician first greeted the monarch after her plane touched down in Canberra on Wednesday, she bowed her head and shook hands with the head of state. But Governor-General Ms Quentin Bryce, the Queen's official representative in Australia, curtsied.
Ms Gillard defended her decision during a number of interviews throughout the day, saying she received advice from protocol staff that the formality was optional.
She told reporters in Queanbeyan, New South Wales: "They are happy with what people are comfortable with."
The Welsh-born prime minister, who is a republican, added: "As I greeted the Queen she extended her hand to shake hands, I shook her hand and bowed my head."
During an interview broadcast on talk radio station 3AW, she was asked if she felt curtsying was demeaning. Ms Gillard replied: "Some things are you, some things aren't... I made a choice, I thought I would feel most comfortable with bowing my head."
But she went on to praise the Queen: "I think many Australians hold her in a great deal of affection and respect and so do I. I mean, what a life, what an incredible life she's lived over so many generations of change, and to see someone play such a steadfast role over so much change, I think, is remarkable."
Cherie Blair, the wife of former prime minister Tony Blair, reportedly refused to curtsy to the Queen. She later revealed that she actually "managed a vague kind of bob" on their first meeting and after that tended to bow instead.
Ms Gillard first met the Queen on the day of the Duke and Duchess of Cambridge's wedding - April 29 - when she was summoned to Buckingham Palace for an audience.
The Australian prime minister has backed calls for her country to become a republic. Speaking ahead of last year's general election, she said that the death of the Queen would be an "appropriate point" for Australia to end the tradition of having a British monarch as head of state.