A board member of Australia's central bank has quit amid an escalating row about his business affairs.
John Howard's party received large donations from Mr Gerard
Robert Gerard stepped down from the Reserve Bank of Australia after claims that he was fighting tax evasion charges at the time of his appointment.
Mr Gerard said he had reached an Australian dollars 75m (£32m; $55m) settlement with tax authorities in 2003 but had not admitted any wrongdoing.
Prime Minister John Howard accused Mr Gerard's critics of a smear campaign.
Mr Gerard is a major donor to the ruling Liberal government.
Revelations that Mr Gerard was involved in a long-running dispute with the tax authorities at the time of his appointment have triggered a political storm.
Opposition politicians have claimed that the government knew about the businessman's background but proceeded with the appointment.
Newspaper reports have claimed that Mr Gerard tried to cover up tax evasion allegations and did not co-operate with investigators, claims which he has strenuously denied.
"This week has been aimed at destroying my reputation and damaging the government," Mr Gerard said in a statement announcing his resignation from the bank.
"Even though I have done nothing wrong and broken no law, the accusations made against me by the media have seriously affected my health and have brought unwanted attention to the board of the Reserve Bank of Australia."