An explosive charge has been used to euthanase a humpback whale stranded off Albany in Western Australia's southwest.
The ailing 9.5m whale was deemed too large to shoot, WA's Department of Environment and Conservation says.
The whale had been stranded on a sandbar in shallow water in Princess Royal Harbour, about 800m from shore, for two weeks.
This afternoon wildlife officers placed sandbags around the whale and positioned a charge over its skull before setting off a precision explosion.
"Our main priority has always been to treat this animal as humanely as possible while nature took its course," department spokesman Mike Shepherd said.
"In the last 24 hours the whale moved a couple of metres from its original stranding position, which was enough to stabilise the whale so that we could carry out the preparations for a controlled implosion to the whale's cranium.
"This was not an option that was available to us until now as the animal, even while terminally sick, was still strong enough to present a serious safety risk to DEC staff and volunteers."
There was a 1km exclusion zone around the juvenile whale before authorities set off the charge and a helicopter looked out for sharks in case of a feeding frenzy.
The carcass of the whale will be removed later this afternoon.