Australian Prime Minister Julia Gillard has faced tough questions over allegations her staff worked on a "victory speech" two weeks before she ousted Kevin Rudd.
Ms Gillard, who took office in June 2010, had said she took the decision to challenge Mr Rudd on the day itself.
But an ABC news programme suggested that preparations were under way well before this.
The controversy comes amid speculation over the ruling Labor Party leadership.
Talk has been rife in political circles recently over the possibility of Mr Rudd, the current foreign minister, making a return to the PM's office.
He has said he is "content" being foreign minister.
Ms Gillard is also suffering in the opinion polls.
On Tuesday morning, Newspoll results published in The Australian newspaper showed that she had lost ground to opposition leader Tony Abbott. While support for him rose three points to 40%, hers dropped to 37%.
'Tense few days'
Ms Gillard was being interviewed by the Australian Broadcasting Corporation's Four Corners programme in an episode on Monday night entitled 'The Comeback Kid?'.
Mr Rudd declined to be interviewed for the program.
Ms Gillard refused to say for certain if she knew the speech was being prepared in advance, but stressed that she did not commission it.
"This was a tense few days for me and the government so I can't specifically say to you when I came to know about the speech," she added on Tuesday morning.
"It could've been on the Wednesday night, it could've been before."
She emphasised that she decided to challenge Mr Rudd for a ballot for the Labor Party leadership ''on the day (she) walked into his office''.
Other allegations that surfaced on the programme include suggestions that US Secretary of State Hilary Clinton had quizzed Australia's ambassador Kim Beazley on the potential leadership change a fortnight before it happened.
On Tuesday morning, members of the Labor Party questioned Ms Gillard's decision to take part in the programme, adding to the brewing tension over leadership issues.
She later said she agreed to the interview request to address questions on ''the outlooks of the government''.
"My job is to answer questions and to explain what the government's doing," she told ABC on Tuesday morning.
"I'm not someone who runs away from questions, and so I did agree to the Four Corners interview."