A top doctor at a Tasmanian hospital falsified the cause of death on patient records, including one reason that defied common sense, an inquiry has been told.

The Launceston General Hospital also allegedly operated outside of its own protocols during its response to the Hillcrest Primary School jumping castle tragedy on December 16, 2021.

It has not been alleged operating outside the protocols affected the standard of care provided to patients following the incident which killed six students.

Amanda Duncan, a nurse and midwife at the hospital, made the accusations on Tuesday during a parliamentary inquiry into ambulance ramping.

She said the hospital's former executive director of medical services Peter Renshaw allegedly falsified medical death certificates and did not report deaths to the coroner as legally required.

"I have received 11 reports from doctors and nurses who have disclosed alleged misconduct relating to the death of a patient, including falsified medical certificates of death," she said.

Ms Duncan said doctors told her they inadvertently discovered the cause of death on medical certificates had been amended by Dr Renshaw without their knowledge.

Dr Renshaw retired from the position in 2022 and was later found to have engaged in misconduct by misleading an inquiry into child sexual abuse in state institutions.

A registered nurse told the inquiry last month that staff at the hospital were concerned causes of death were not being correctly reported to the coroner.

A health department spokesman said preliminary investigations were under way into last month's allegations.

"The department is aware of further associated allegations raised during (Tuesday's) hearings and will seek additional identifying information to support further investigation into these reports," he said.

Ms Duncan said the hospital declared a "code brown" on the day of the Hillcrest incident, a protocol that required a pause on elective surgery.

However, she said management decided to proceed with elective and non-urgent cases.

She said it was "sheer luck" a child was able to be received for emergency surgery.

Ms Duncan said no staff members alleged patient outcomes were adversely affected by the decision to not follow the protocol.

She referenced a case in which a patient died in the emergency department following unsuccessful resuscitation.

She said several doctors and nurses involved felt the patient may have survived if their case had been reviewed in a timely manner and if resuscitation occurred on a hospital bed.

"They expected a coronial investigation," Ms Duncan said.

"Doctors and nurses have stated to me the cause of death Dr Renshaw documented on the deceased's medical certificate defied basic common sense."

Ms Duncan, who provided further information to the inquiry privately, has called for a broad investigation into health failings in Tasmania.

Premier Jeremy Rockliff told reporters he had yet to be fully briefed on the latest evidence.

"Anything that arises from the (inquiry) process of course will be fully investigated as it should," he said.