Two senior officials at Metro North Hospital and Health Service, which spans from Brisbane's north and parts of the Moreton and Somerset regions, have been referred to the Crime and Corruption Commission (CCC).
Chief executive Malcolm Stamp and executive director of corporate services Scott McMullen were stood aside pending an investigation into matters that are yet to be revealed.
Statements issued by Queensland Health and Minister Lawrence Springborg's spokesman did not explain why the two senior bureaucrats were suspended, but it was confirmed the pair had been referred to the state's corruption watchdog.
Labor's health spokesperson Jo-Ann Miller said Queenslanders have a right to know what was going on at the service.
"This Government must tell the truth about why they have suspended the CEO and another senior executive from their offices," she said.
"This is an extraordinary turn of events dealing with Queensland's biggest and busiest hospitals that also hold the biggest budget.
"Taxpayers, patients and staff deserve to know what is happening."
Mr Stamp had over 39 years' experience in the United Kingdom's National Health Service (NHS) and during his career secured the largest public-private sector funding agreement to develop the new Norfolk and Norwich University Hospital.
The service's board chairman, Dr Paul Alexander, sent an email to staff on Monday advising of the suspensions and explained an investigation was being coordinated by Minter Ellison Lawyers.
"The board will ensure staff receive appropriate information about the outcome of the investigation when completed," he said.
Chief operating officer Kerrie Mahon will step in as acting chief executive and chief financial officer, Rob Dubery, will fill in for Mr McMullen.
"The implementation of clinical streams and the process of organisational transformation will continue while these interim arrangements are in place," Dr Alexander said in his email.
"The board has met with the executive leadership team, including the executive leads of facilities, professional streams and new clinical streams, to discuss these arrangements."