The bacteria were found in an ice core taken from the bottom of Lake Vostok, which is covered by an ice sheet more than two miles thick.
Researchers tested the sample, saying that its DNA is different enough from existing records to count as its own species.
According to the Russian news site RIA Novosti, Sergei Bulat, a researcher at the St. Petersburg Nuclear Physics Institute, said:
“After excluding all known contaminants…we discovered bacterial DNA that does not match any known species listed in global databanks. We call it unidentified and ‘unclassified’ life.”
Full details of the discovery are still vague, though scientists are excited to have found signs of life in one of the coldest places on Earth. A U.S.-funded team has also drilled into a separate ice sheet in Antarctica, and says that they have encountered bacteria as well.
The sample may have been isolated as early as 17 million years ago, and this could be the first time the water has seen sunlight in millennia.