The Victorian government has questions to answer over the Royal Flying Doctor Service missing out on the contract to run the state's air ambulances, the opposition says.
Ambulance Victoria last week awarded a 10-year, $70 million contract to a private, foreign-owned airline in a move that is expected to cost more than 30 jobs.
Pel-Air, a subsidiary of regional airline Rex, which is majority-owned by two Singaporean men, will now run the service.
Opposition Leader Ted Baillieu said the government must reveal on what basis the contract was awarded to Pel-Air.
"I would have thought there was plenty of reason to think the service was being well provided (by the flying doctors)," he told reporters in Melbourne.
"If it's a question of capacity or price, then the premier needs to advise Victorians on what basis that decision was made.
"It's obviously a significant and symbolic contract."
Victorian Premier John Brumby said he was not aware of the decision and government agencies were responsible for tendering.
He said a contract committee made recommendations to the government on tenders and the process was overseen by probity auditors.