Bulat said that the interest surrounded one particular form of bacteria whose DNA was less than 86 percent similar to previously existing forms.
"In terms of work with DNA this is basically zero. A level of 90 percent usually means that the organism is unknown."
He said it was not even possible to find the genetic descendants of the bacteria.
"If this had been found on Mars everyone would have undoubtedly said there is life on Mars. But this is bacteria from Earth."
Bulat said that new samples of water would be taken from Lake Vostok during a new expedition in May.
"If we manage to find the same group of organisms in this water we can say for sure that we have found new life on Earth that exists in no database," Bulat said.
Exploring environments such as Lake Vostok allows scientists to discover what life forms can exist in the most extreme conditions and thus whether life could exist on some other bodies in the solar system.
There has long been excitement among some scientists that life theoretically could exist on Saturn's moon Enceladus and the Jupiter moon Europa as they are believed to have oceans, or large lakes, beneath their icy shells.