Australia's opposition leader Tony Abbott admitted to some childish behaviour in his student days, but denied reports he intimidated a woman by punching a wall near her head.
Australia's political leaders have been subject to intense scrutiny of their past in recent weeks, with Labor Prime Minister Julia Gillard's private life in the 1990s under the microscope due to her relationship with an ex-union figure.
The spotlight has now turned on Abbott, the conservative Liberal Party leader favoured by opinion polls to win next year's election, with claims he intimidated a female student after she beat him in a student election.
A report in the Quarterly Essay said Barbara Ramjan thought Abbott was coming to congratulate her when she was elected president of Sydney University's Student Representative Council in 1977.
"But no, that's not what he wanted. He came to within an inch of my nose and punched the wall on either side of my head," Ramjan is quoted as saying.
Abbott on Friday denied the incident and said the allegations were "the product of the Labor Party dirt unit".
"I had no recollection of it because it had never happened, simple as that," Abbott told the Nine Network.
But he did admit to referring to rival Ramjan as "chairthing" after she asked to be called "chairperson" rather than "chairman".
"I probably was guilty of using that silly phrase," Abbott said.
"A lot of childish and immature things happen on student councils and I think I probably was guilty of using that silly phrase.
"Silly things happen on campus, alas."
Gillard leads a Labor minority government with the aid of a Greens MP and several independent lawmakers after a deadlocked election in August 2010 but both Gillard and Abbott remain unpopular with voters, according to polls.
The prime minister last month fronted a press conference at which she dealt with "false and highly defamatory" accusations about her departure from law firm Slater & Gordon some 17 years ago.
Questions centred on her legal advice to help set up an entity for the Australian Workers Union and her partner at the time, AWU official Bruce Wilson, who was allegedly corrupt.
"For a number of months now there has been a smear campaign circulating on the Internet relating to events 17 years ago," Gillard said.
"Much of the material in circulation is highly sexist."