State Department of Agriculture investigators are investigating reports that iguanas are being illegally raised on O'ahu.

The issue came to light after an iguana was captured along a Waimanalo roadside Monday afternoon and turned over to Kailua police.

But Janelle Saneishi, Agriculture Department public information officer, said yesterday that investigators aren't sure what to make of stories about outlaw iguana breeders.

"That would be illegal," said Saneishi, who added that Hawai'i's laws on breeding exotic species such as iguanas carry stiff penalties of up to $200,000 in fines and three years in prison. "We're trying to find out. I know our investigators are trying to get more information about it."

Retired Honolulu Police Sgt. Leighton Fujinaka was at the Kailua station when area residents Dennis Gaspar and Rodney Texeira brought the lizard in. Fujinaka said the critter was larger than a monster gecko on steroids.

"It was huge," said Fujinaka. "It looked like a little dinosaur."

Fujinaka said Gaspar and Texeira spotted the three-foot lizard moving through roadside brush in Waimanalo at around 2:30 p.m. Monday. He said Gaspar used a metal plumber's snake to coax the reptile into a blue recycling bin.

"I don't know how they got it in there, but they did it," he said.

Saneishi said stories about illegally bred iguanas have been around O'ahu for a while, but not as long as the iguanas themselves, which have existed in some parts of the island for decades.

"From what I understand, they came in, or were allowed in, at some point before we had animal quarantine rules," she said. "And they established themselves in some areas — mainly Waimanalo, but we have found them in Waipahu and other places. They have no natural predators here."

Saneishi said the captured iguana is in quarantine, doing fine, appears healthy, and won't be destroyed. It will first be offered to Island zoos, should any want it. Otherwise, she said, the creature would be shipped to a reptile farm in Florida.

Full-grown iguanas can be 6 feet long. They are native to Mexico and South America. While they mostly eat vegetation, Saneishi said, they've been known to disturb bird nestlings and to devour bird eggs.

She advises people who have iguanas, or any other illegal animal, to turn the creatures in under the state's amnesty program, which offers immunity from fines or prosecution. Such animals can be turned over to the Ag Department, a municipal zoo, or the Hawaiian Humane Society — no questions asked.

Reach Will Hoover at whoover@honoluluadvertiser.com.