An exclusion zone has been established on a NSW beach around a dead humpback whale which authorities had feared could explode.
The 12.7-metre female whale washed up on Big Hill Beach near Crescent Head on Wednesday night and inflated during Thursday, whale welfare group ORRCA told AAP on Thursday.
It's a natural process for marine animals to bloat and blow up when they become beached, ORRCA spokeswoman Jools Farrell said.
But Ms Farrell says there's no longer a risk of the whale exploding with national parks officers in the process of removing it with heavy machinery.
The beach remains closed while the operation is underway.