The ABC has seen Townsville Hospital documents that show more than 1,200 outpatients are on the waiting list for heart scans.
The most urgent outpatients are waiting an average of three months to be seen.
The document said the hospital would hire two locum staff to get through the waiting list but the Together Union’s Billy Colless said the hospital had overlooked its own staff.
“They’re going to pay them four times the amount they would actually pay staff locally to do the job they’re already doing,” he said.
He said local staff believed they could do the job.
“The health board would rather go and give those resources to an employee that comes from Brisbane rather than a local,” he said.
The Townsville Hospital said the outsourcing was only temporary until it hired a permanent staff member.
It said the appointment would help reduce waiting lists and staff had been consulted.