Australian Customs national manager investigations Richard Janeczko said yesterday smuggled wildlife was at least a $20billion global industry.

''It's considered the third-largest criminal activity in the world, after drugs and weapons,'' he said.

Animals bred in captivity can be legally imported to Australia with a permit from the Federal Government.

Police and wildlife experts suspect the 1.5m alligator, now named Ali II, was a pet that grew too big because it was in good health when it wandered into the Noonameena Scout Camp on Monday afternoon.

However, police say no one in the area was licensed to keep an alligator, suggesting it was being illegally held.

Mr Janeczko said usually only very small alligators were smuggled into Australia, sometimes mailed in parcels or even hidden on people.

''They hibernate so they put them with something cold or give them a drug and hope they won't stir too much,'' he said.

Batemans Bay police inspector Gary Megay said investigations were continuing into the origins of the Pambula alligator.

''If it was a crocodile you might be able to say someone had picked it up in the Northern Territory and brought it back when it was little. But not an alligator, that's much too hard to explain,'' he said.

Australian Reptile Park general manager Mary Rayner quashed scuttlebutt yesterday that the Pambula alligator might have been stolen years ago from the park near Gosford.

The only theft in recent time had been that of the park's famous alligator, Mr Cranky Pants, which was stolen in 2004 but found alive a couple of days later in a nearby creek. At the time it was estimated the 1.2m alligator could have fetched $5000 on the black market.

Ms Rayner suspected a reptile enthusiast owned the Pambula alligator, purchased when it was much smaller.