A live shark dumped on the doorstep of an Australian country newspaper office had local police puzzled, with authorities vowing to charge the person who left it with animal cruelty.

The juvenile Port Jackson shark, which measured around 70 centimeters in length, was left in darkness outside the office at Warrnambool, on the coast of southeast Victoria state. "We arrived and poured some water on it just to see if it was still breathing and it kicked around for a little while," Constable Jarrod Dwyer told state radio.

"I walked over to McDonalds and borrowed a bucket off them and filled it up with water, and we picked the shark up and put it inside it and then drove it down to the breakwater and released it back into the water," he said.

Port Jackson sharks can grow up to 1.6 metres long (5.5 ft) and typically feed on crustaceans, sea urchins, and fish. They are nocturnal and common across Australia's southeast coast. Dwyer said the newspaper was unaware why anyone would leave a shark to die outside.

"They had no ideas of any person that wished them any harm or wished to send them any type of message, so we're a little dumbfounded," he said.