Two scuba divers were allegedly left behind by a tour operator and rescued by a Rottnest ferry

Crew members on board a ferry spotted two scuba divers treading water in the ocean after they were allegedly left behind by a tour operator.

Authorities are investigating after two scuba divers were allegedly left behind by a tour operator in the Indian Ocean only to be spotted by a ferry crew returning to the mainland.

Rottnest Fast Ferries was on its way back to Hillarys Boat Harbour, in Perth’s north, when a crew member saw the divers treading water a few nautical miles offshore and pulled them to safety on March 2.

The divers were allegedly in the water for several hours before they were taken to shore and one was hospitalised, ABC reported.

Two scuba divers were allegedly stranded for several hours in the Indian Ocean before crew members on board Rottnest Fast Ferries spotted them in the water and pulled them to safety. Picture: Facebook

The Australian Maritime Safety Authority is aware of the incident and are investigating to ensure the company involved complied with marine safety legislation.

An AMSA spokesman said incidents involving passengers on board domestic commercial vessels must be reported.

“AMSA takes the safety of passengers and crew very seriously and would not hesitate to take swift and strong action should a breach of safety regulations or procedures be identified,” a spokesman said.

“It is too early to discuss what penalties may apply.

“The outcome of an investigation may include the development of strategies and interventions to improve marine safety and protection of the environment or the undertaking of enforcement action.”

A Perth Diving Academy spokesman said they would not comment on the incident until AMSA had completed its investigation.

Originally published as Two scuba divers were allegedly left behind by a tour operator and rescued by a Rottnest ferry