Officials killed 157 killer whales stranded on a beach in Tasmania.

Wildlife veterinarians had to conduct a mass euthanasia of the beached sea creatures in Arthur River on February 18.

Aerial footage shows the hapless whales lying on the shore. In another clip, authorities can be seen injecting euthanasia solutions on the animals.

Marine conservation experts and wildlife veterinarians reportedly arrived at the remote site to assess the situation, initially finding 136 whales still alive. However, the impassable terrain, rough ocean conditions, and lack of specialist equipment led them to determine that euthanasia was the only humane option.

Incident Controller Shelley Graham said: 'I'm really proud of the exceptional effort all members have put in to get the best animal welfare outcome possible.'

Wildlife veterinarian Sarah Michael, who oversaw the euthanasia, said that she is confident euthanasia was the right decision for this complex situation.

The Department of Natural Resources and Environment Tasmania is currently conducting post-mortem investigations and necropsies to study the whales' health.

Local media reported that the carcasses will be left to decompose naturally due to the rugged terrain.

Authorities have closed roads and beaches in the area and are urging the public to stay away.

False killer whales are a species of oceanic dolphin that resemble killer whales in appearance. They are highly social animals, often forming pods of up to 50 members. They can also form pods with other dolphin species, such as the common bottlenose dolphin.

The false killer whale is listed as Near Threatened on the IUCN Red List and is protected under various international agreements.