David Cameron gave his "full support" to the Culture Secretary Maria Miller after a Parliamentary sleaze watchdog launched an investigation into her expenses.
The probe came after The Daily Telegraph reported that the Cabinet minister claimed more than £90,000 for a second home where her parents lived.
The Minister claimed £90,718 - almost the maximum permitted - for a house where her parents had apparently been living since 1996.
Miller said two audits into her expenses had been carried out; one by former civil servant Sir Thomas Legg - who was called in to review all MPs' claims at the height of the expenses scandal - and the other by the Conservative Party.
Asked by the Evening Standard whether Sir Thomas was aware that her parents were living at her designated second home, Mrs Miller said: "I obviously spoke to the Fees Office about my claims and they were happy that everything was in order."
Miller also denied that she had used her position overseeing the post-Leveson reforms of press regulation to ward off the Telegraph.
Her special adviser, Joanna Hindley, reportedly told Telegraph reporters investigating Miller's expenses: "Maria has obviously been having quite a lot of editors' meetings around Leveson at the moment. I am just going to flag up that connection for you to think about."
David Cameron gave his backing to the Culture Secretary, saying: "Maria Miller does an absolutely excellent job and she has my full support.
"A newspaper has asked her a number of questions and as far as I can see she has excellent answers to all those questions."
However, The Daily Telegraph has published a timeline of the sequence of events over its investigation "to set the record straight."
It has also published emails between Maria Miller and the paper's editor Tony Gallagher.