The landslip, up to 300 metres wide, took place at Inskip Point in Queensland, reports the BBC.
The authorities were however, not sure whether the incident took place on Sunday or Monday.
"It's likely this erosion has been caused by the undermining of part of the shoreline by tidal flow, waves and currents," Queensland's Department of Environment and Science said in a statement.
In 2015, about 140 people were evacuated after a 200 metre-wide landslip claimed part of a campground in the state.
After that incident, Queensland reviewed the stability of the peninsula and set up exclusion zones around areas deemed to be at risk of erosion.
A smaller landslip hit the peninsula in 2016.
Helicopter pilot Glen Cruickshank said he saw the change while flying over the popular sand peninsula, about 250 km north of Brisbane, on Monday.
"It is far bigger than the last two - it's a right big chunk that's just been sucked down," he told the BBC.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
