Contrary to rumors, there are no three-headed pigs here.

Still, this tiny, high-security island, only a mile and a half off Long Island's prosperous North Fork, is the site of the Plum Island Animal Disease Center, where scientists study some of the world's most infectious animal viruses.

It is the lab made famous in Nelson DeMille's 1997 bestseller "Plum Island," about stolen viruses and murdered scientists. And because the public is usually kept out, there is wild speculation about what goes on inside the lab 135 miles east of Manhattan.

Now that the Agriculture Department wants to upgrade the laboratory, allowing scientists to also study animal diseases that endanger humans, officials are going out of their way to ease public concern, addressing local residents and taking elected officials and reporters on tours.

It is not likely to be an easy sell to residents of the east end of Long Island, which boasts the rich and famous in the Hamptons on the South Fork and miles of rolling wine country on the North Fork.

More than a decade ago, they helped halt construction of the Shoreham nuclear power plant. More recently, they lobbied the Energy Department into permanently shutting down a nuclear reactor at the Brookhaven National Laboratory.

Wilda Martinez, area director for the Agricultural Research Service, told about 100 people at a public hearing at the Greenport American Legion building that a cutting-edge lab on Plum Island is essential to protecting public health.

She warned that new microbes and diseases are spreading--citing the West Nile virus blamed in the deaths of six people in New York in September.

"The protection afforded by ocean barriers and geographical separation will no longer prevent the introduction of foreign animal diseases," Martinez said.

What's being considered is the upgrading of the lab to "Biosecurity Level 4"--the highest security level.

Under the lab's current security level, reporters and photographers given a tour last week were ordered to strip naked and don plastic coveralls and clean sneakers--standard procedure for Plum Island employees. Photographers had to carry waterproof cameras that could be soaked in acetic acid after the tour. Everyone had to shower for at least three minutes before leaving.

Rep. Michael P. Forbes (D-N.Y.), whose district covers the east end of Long Island, said he has serious reservations about upgrading Plum Island.

"I think we need additional information about their plans," Forbes said. "I am not outright opposed to it, but neither have I embraced the idea."

Ed Barrett, a retired chemistry professor from Marion, asked if the BSL-4 lab could be located "somewhere where there is no possibility that some kind of error [will] cause something that could be catastrophic for us?"

Not everyone was so worried. Greenport Mayor Dave Kapell was one of the local elected officials who toured the facility.

"In every place that I went in that lab, I would see people that I see every day in the village," he said. "These are all our friends and our neighbors that operate this place.

"Frankly, if they're not scared, I don't feel scared."

CAPTION: Pigs are quarantined in airtight pens at the Plum Island Animal Disease Center, where scientists study some of the most infectious animal viruses.

CAPTION: Luis Rodriguez demonstrates the safety measures at the Plum Island Animal Disease Center. The government wants to upgrade the high-security laboratory.