It comes at a time when the airborne killer disease has reached epidemic proportions around the world.

The team from the Pasteur Institute in France and Britain's Sanger Centre have unravelled the entire 4,000-gene sequence or genome of the TB bacillus.

The discovery should make it easier for other scientists to develop new drugs and vaccines against the disease.

The World Health Organisation predicts it will have infected almost one billion people by the year 2020.

It expects that 70 million of these will die unless new treatments are found. Already three million die of the disease every year and new drug-resistant strains are developing.

Landmark discovery

Dr Stewart Cole, one of the researchers, called the finding "a landmark in the history of tuberculosis research" as it opens up thousands of new avenues for research.

Scientists have cracked the genetic code for other diseases, such as Lyme disease, but the TB breakthrough is the most complex genome yet.

Dr Cole said it was the most important one to date. "It will certainly lead to drug companies and vaccine designers taking more interest in the subject because they have all this free data there at their disposal," he said.

The research was funded by the Wellcome Trust and is published in this week's issue of 'Nature'.