A U.S. Government advisory board took the unprecedented step Tuesday in asking two science journals to refrain from publishing certain details from two new papers that describe how to produce what experts warn is a far more deadly version of the Asian “bird flu” virus.

The new strain has the potential to infect and kill millions of people, according to the London-based Independent, which initially reported the story.

The request is being made by the National Science Advisory Board for Biosecurity (NSABB), which was established shortly after the anthrax attacks of 2001 to provide advice to federal officials regarding biological research and potential biological threats.

The board, which consists of 23 health, science and biosecurity professionals, spent weeks reviewing the manuscripts before concluding, and making the recommendation, that the articles “not include the methodological and other details that could enable replication of the experiments by those who would seek to do harm,” according to a Washington Post story published earlier today.

Their recommendation, however, cannot force the two scientific journals from publishing the procedures for reproducing the virus. Instead, their advice is served up to leaders of the Department of Health and Human Services.

The two journals planning to publish the articles are Science, an academic journal of the American Association for the Advancement of Science and Nature, a weekly science journal founded in Britain in 1869.

“The fear is that if you create something this deadly and it goes into a global pandemic, the mortality and cost to the world could be massive,” a senior scientific adviser to the US Government told The Independent, speaking on condition of anonymity. “The worst-case scenario here is worse than anything you can imagine,” the individual said.

At the heart of the concern is the ability of researchers to mutate the so-called H5N1 strain of avian influenza so that it can be transmitted easily through the air in coughs and sneezes. Until this the reports began circulating for review, scientists thought that H5N1 bird flu could only be transmitted between humans who were in close physical proximity to one another.

What has critics alarmed is that the H5N1 strain killed 60% of those infected with the virus, making it one of the deadliest forms of influenza in modern history.

According to reports, university-based scientists in the Netherlands and Wisconsin created a version of the so-called H5N1 influenza virus that is easily transmissible between ferrets, the lab animals that most closely mirror human beings in flu research.

Likening the development to revealing instructions on how to make a nuclear weapon, the scientist told The Independent “The life sciences really haven’t encountered this situation before. It’s really a new age.”

According to The Independent, a senior source close to the Biosecurity board, who wished to remain anonymous, the National Institutes of Health, which funded the work, is about to make a decision on how much of the scientific paper on the H5N1 super strain should be published, and how much held back.