The deadly virus is a genetically tweaked version of the H5N1 bird flu strain, but is far more infectious and could pass easily between millions of people at a time.
The research has caused a storm of controversy and divided scientists, with some saying it should never have been carried out.
The current strain of H5N1 has only killed 500 people and is not contagious enough to cause a global pandemic.
But their are fears the modified virus is so dangerous it could be used for bio-warfare, if it falls into the wrong hands.
Virologist Ron Fouchier of the Erasmus Medical Centre in the Netherlands lead a team of scientists who discovered that a mere five mutations to the avian virus was sufficient to make it spread far more easily.
He conducted his tests on ferrets as the animals have become a model of choice for influenza and have similar respiratory tracts to humans.
Fouchier is so prepared for a media storm that he has hired an advisor to help him work on a communication strategy.
The research done was part of an international drive to understand H5N1 more fully.
Fouchier admitted the strain is 'one of the most dangerous viruses you can make' but is still adamant he wants to publish a paper describing how it was done. Read More