A research on mutant bird flu has been stopped for the time being in the wake of fears that it could be exploited by terrorists, say scientists.
The H5N1 strain of bird flu is potentially fatal when caught by humans.
However, its impact has so far been limited because it is not easily transmissible between humans.
Now, an international team, led by Erasmus University in the Netherlands and the University of Wisconsin-Madison in the US, has altered the strain, and found it was much more easily passed between ferrets.
This raised bio-terror fears among the scientists who have halted the research, the 'BBC' reported.
The team has called for an 'international forum' to debate the risks and value of the research, in a letter published in the 'Science and Nature' journal.
A senior US health official said that not everyone needs to know how to make a lethal virus. However, the World Health Organisation has said in a statement that limiting access to the research would harm an agreement between its members.
Even the scientists claim that knowledge of more infectious strains before they mutate in nature is valuable for public health.
"More research is needed to determine how influenza viruses in nature become human pandemic threats so that they can be contained before they acquire the ability to transmit from human to human, or so that appropriate countermeasures can be deployed if adaptation to humans occurs," they said.