A baggage handler of Qantas caught last week a 60-centimetre crocodile at its cargo hold. The reptile escaped from its cage while mid-air on a Brisbane-Melbourne flight.

A Qantas spokesman said on Monday that the animal was recaptured and safely secured when the plane arrived in Melbourne.

The cargo company responsible for the shipment of the crocodile, Australian Air Express, is investigating how the reptile escaped from its cage in the plane's cargo hold. The focus of the probe is if the cage was loaded properly.

John Lever, owner of the Koorana Crocodile Farm, explained to ABC that to transport a crocodile, it should be placed inside a scotch cylinder with holes for ventilation.

Qantas is not the first airline to have loose animals. Air Force pilots in India sought snake charmers after two MIG-21 fighter jets were grounded because of a snake which mechanics spotted slithering in the plane's cockpit and another snake wrapped around the undercarriage after the jet landed.

The Indian Air Force report pointed out that apart from the risks the snakes post to the pilot, the vipers also pose danger of biting or puncturing linings of the aircraft's oxygen or fuel systems or electrical connections that may cause a serious emergency.

Meanwhile, wildlife rangers who were setting crocodile traps in Deep Creek, Kewaraa Beach near Cairns discovered the carcass of a large saltwater crocodile with its head cut off. The rangers said the 2.5-metre reptile was probably lured with a baited stainless steel hook and was eventually beheaded and left floating upside down in the water.

They theorised the killing of the croc was in response to the snatching of a two-year-old coolie cross dog by a crocodile in the same area based on a large warning sign left in the area that a dog was eaten by a crocodile on Sept 20, 2012. However, the croc killer is apparently the owner of the eaten dog.

Ben Woods, the owner of the dog named Angus, pushed for removal of crocodiles from local waters or culled. However, he said the culling should not be done in a savage way.

"There's a difference between culling and just cutting off a crocodile's head and leaving it there in the water. It's a bit crook leaving a croc down there with no head on it - as much as I hate the croc, I wouldn't want anyone to have to see that," The Herald Sun quoted Mr Woods.