The far-reaching audit that exposed sordid details of the government sponsorship program carried a hefty price tag of nearly $10 million.

Figures obtained from the office of Canada's auditor-general show taxpayers spent $9.6 million on the probe that unearthed the sponsorship scandal, rule-breaking in a $101-million purchase of luxury government jets and a chronic neglect of the nation's cultural heritage.

Opposition MPs and the Canadian Taxpayers Federation say the alarming cost is money well spent for holding the government to account. But they insist the expense incurred by Sheila Fraser and her team of investigative auditors could have been avoided if the government had more stringent controls over public funds and stronger legal protection for bureaucrats who report crooked colleagues.

"If there was any semblance of whistleblower protection, we could have avoided that outlay of money," said NDP MP Pat Martin.

Calling her the "best friend" of taxpayers, John Williamson, of the Canadian Taxpayers' Federation, said the probe was worth its cost.

"Democracy, oversight and accountability -- there's a price tag to that," he said.