An Australian researcher claims the swine flu, which has killed at least 64 people so far, might not be a mutation that occurred naturally but a man-made product of genetic experiments accidently leaked from a laboratory -- a theory the World Health Organization is taking very seriously.
Adrian Gibbs, a scientist on the team that was behind the development of Tamiflu, says in a report he is submitting today that swine flu might have been created using eggs to grow viruses and make new vaccines, and could have been accidently leaked to the general public.
"It might be some sort of simple error that's not being recognized," Gibbs said on ABC's "Good Morning America."
In an interview with Bloomberg Television, Gibbs admitted there are other ways to explain swine flu's origin.
"One of the simplest explanations if that it's a laboratory escape, but there are lots of others," he said.
In the United States, the Centers for Disease Control and Prevention says it has reviewed Gibb's report but says there is no evidence to support his claims, a conclusion many experts found comforting.
"Technically it's plausible but not likely," Christopher Ohl, an associate professor of medicine at Wake Forest University School of Medicine, and a specialist in infectious diseases.
"In this case I'm not concerned that this virus represents anything other than a naturally occurring mixture of viruses happening in nature," concluded Dr. Julie Gerberding, an infectious disease expert and the former director of the CDC.
Regardless of the validity of Gibb's claims, he and several experts say that just bringing the idea of laboratory security to the public's attention is important.
"There are lives at risk," Gibbs said. "The sooner this idea gets out, the better."
In 2001, foot-and-mouth disease led to the slaughter of more than 6 million animals, all after a vial went missing from a research laboratory in the United Kingdom.
Since then, however, experts said lab security and regulations have been getting tighter and better.
"Laboratories have a lot of security from having this happen, and it's very unlikely," Ohl said of the new theory about swine flu's origin.
Though Outbreak Seems to Slow, Experts Warn of Possible Surge
Even though the swine flu outbreak in Mexico is waning and the country reopened schools and businesses earlier this month, international health officials have still not ruled out the chance of a new surge in swine flu cases.
And infectious disease experts said that it is too early to say that we are out of the woods when it comes to the disease.
Dr. Gregory Poland, professor of medicine and infectious diseases at Mayo Clinic in Rochester, Minn., said that it is "way too early to 'pull back' yet in our level of concern.
"Always expect the unexpected from influenza," Poland said.
"While there are some signs that are reassuring, less severity, decrease cases in Mexico, et cetera, I believe we are not out of the woods yet," agreed Ohl. "I am concerned this virus is with us for a while. It could change, become more virulent, have an increased secondary transmission rate ... in the future."
The virus, according to the World Health Organization report today, has spread to 33 countries, 6,497 cases have been reported and more than 60 people have died after infected.
The WHO continues to urge individuals to "delay travel plans" in hopes of stemming the spread of the disease.
ABC News' Ammu Kannampilly and Theresa Cook contributed to this report.