A 3.5m great white shark has been spotted off a Falcon beach, near where the Mandurah Pro surfing competition is taking place.
The shark was sighted by a member of the public about 500m off Avalon Beach around 8am on Monday.
Surfing Western Australian Events Manager Justin Majeks said despite the sighting, the Mandurah Pro is still going ahead.
"We were made aware by some fishermen early this morning that they spotted a shark at the back of our competition area," he said.
"We've got a good safety protocol in place.
"We've got a drone in the air and water safety officers on deck too and we haven't seen or detected anything else."
The Mandurah Pro is a four-day surfing event which finishes on Tuesday.
Public report 3.5m white shark sighted 08:00hrs 15/10, Avalon Beach, Mandurah 500m offshore , 200m north of Avalon beach..
— Surf Life Saving WA (@SLSWA) October 15, 2018