FOUR Mile Beach has been closed for the rest of the day after a crocodile, estimated to be at least 4.5 metres, was spotted this afternoon.

The massive croc was sighted by lifeguards from the Port Douglas Surf Life Saving Club near the rocks at the northern end of the beach just after 1pm.

They followed it south along the beach towards the Mowbray River, before losing sight of the animal.

The sighting was reported to the Department of Environment and Heritage Protection. Lifeguards wish to inform the public the beach will remain closed this afternoon, but should reopen tomorrow morning.

The beach was also closed last weekend due to the presence of marine stingers.