Scientists are planning to bring an ancient 'giant virus' discovered in Siberia, back to life to find out if it could be harmful to animals or humans.
The 30,000-year-old virus is known as Mollivirus sibericum and it is the fourth prehistoric virus to be discovered since 2003.
A team from the French National Centre for Scientific Research uncovered it while studying a sample of frozen soil originating from the Kolyma lowland region of Russia
Their aim is to find out how global warming could play a role in making these viruses a real threat as frozen regions start to thaw.
Writing in the PNAS journal, where the study was published, scientists explained: "The fact that two different viruses could be easily revived from prehistoric permafrost should be of concern in a context of global warming."
To qualify as a "giant", a virus has to be longer than half a micron, a thousandth of a millimetre (0.00002 of an inch), Phys.org reports.
Mollivirus sibericum is 0.6 microns long, containing a genome that code for more than 500 proteins.
"A few viral particles that are still infectious may be enough, in the presence of a vulnerable host, to revive potentially pathogenic viruses," one of the lead researchers, Jean-Michel Claverie, told AFP.
"If we are not careful, and we industrialise these areas without putting safeguards in place, we run the risk of one day waking up viruses such as small pox that we thought were eradicated," he added.