Cardiac surgery at one of Melbourne's busiest hospitals has been temporarily suspended due to a bypass equipment fault.

Staff became aware of a technical issue involving a cardiopulmonary bypass machine at The Austin Hospital in Melbourne's northeast on Friday, Austin Health confirmed.

The discovery was made when a patient's cardiac surgery was interrupted.

Also known as a heart-lung machine, the device can take over the jobs of a patient's heart and lungs during a procedure.

Work is underway to ensure patients scheduled for cardiac surgery this week will be treated elsewhere, an Austin Health spokeswoman said.

"While we undertake investigations to determine the cause of the equipment fault, cardiac surgery at Austin Hospital has been paused," she said.

It remains unclear when cardiac surgery will resume at the hospital.

The incident comes weeks after a patient was harmed when another piece of equipment malfunctioned during heart surgery.

The recent technical issue on Friday is separate to the previous incident and a different device was involved.

Both machines have been removed from clinical use.

Safer Care Victoria has been informed.