A baby humpback whale will be tested for H5N1 bird flu after it washed up and died on a beach in Sydney’s south.

The 4.5-metre male calf was found at Greenhills Beach in Cronulla at 6.30am on Friday.

A baby humpback whale was stranded and died at Greenhills Beach - approx 2km north of Wanda Beach Surf Life Saving Club int he Cronulla region. The calf was believed to be a few days old.

The 4.5 metre male calf was found at Greenhills Beach in Cronulla at 6.30am on Friday. Thomas Hollywood

A member of the public alerted the Organisation for the Rescue and Research of Cetaceans in Australia (ORRCA).

The rescue group were called to assess the animal alongside the NSW National Parks and Wildlife, Gamay Rangers and Sutherland Shire Council.

The responding agencies tried to save the whale but he died shortly after they arrived.

The whale will be removed from the beach and managed in accordance with cultural protocols, in collaboration with the Gamay Rangers.

ORRCA president Ashley Ryan said the whale would undergo H5N1 avian influenza testing as part of standard biosecurity procedures.

“At this stage, it is not yet known whether a full necropsy will be undertaken,” Ryan said.

“The cause of the stranding is unknown at this stage.

“There are many reasons why whales can become stranded, including illness, injury, separation from their mother, navigational challenges or other natural factors.

“It is too early to determine what led to this particular incident.”

NSW Department of Primary Industries Fisheries and local lifeguards have been notified so appropriate SharkSmart alerts can be implemented as a precaution.

“ORRCA thanks the member of the public who reported the whale promptly,” Ryan said.

“Early reporting provides the best possible opportunity for trained responders to assess an animal and determine the most appropriate course of action.

“Members of the public are reminded to keep well away from stranded marine mammals, keep dogs on leads and away from the area, and follow directions from emergency personnel.”

Anyone who encounters a stranded, injured or entangled whale, dolphin or seal should immediately contact the ORRCA 24-hour Rescue Hotline on (02) 9415 3333 or NPWS.