Sydney - An Australian family were distraught on Thursday after rangers took away their 13-year-old pet saltwater crocodile.

A neighbour in their suburban Sydney street alerted authorities to 2,5m Fang.

Fang, whose home was an enclosure in the back yard, was known to all the children in the neighbourhood.

Eric Cole didn't blame the National Parks and Wildlife Service (NPWS) for enforcing the law.

"They've got their job to do and I have to say that after dealing with the NPWS in this state for the past 30 years, they've been absolutely professional at all times," Cole told Australia's AAP news agency.

"He just grew and grew and grew and I've probably been lax," he added. "You have to have a permit to hold it, and if the permit isn't renewed, you then have to give the animal up." - Sapa-DPA