The Konstantinov St. Petersburg Nuclear Research Institute is finalizing tests of water samples taken from the Antarctic sub-glacial lake Vostok last year.
Eukaryote genetics laboratory head Vladimir Korolyov told Interfax they did not find any life forms other than contaminants.
"We found certain specimen, although not many, but all of them belonged to contaminants (microorganisms from the bore-hole kerosene, human bodies or the lab). There was one strain of bacteria which we did not find in drilling liquid, but the bacteria could in principal use kerosene as an energy source," Korolyov said.
"That is why we can't say that a previously-unknown bacteria was found," he added.
The scientist said that Vostok water mixed with the drilling liquid would yield meager results and they would have to wait for pure water samples.
"Deepwater devices designed at our institute will be used next year for taking pure water with pure samplers. For now we'd rather not say something we will be unable to whitewash even with the crystal clear Vostok water," he said.
Russian scientists were the world's first to reach the surface of Lake Vostok in early February 2012. The lake had been sealed off under the Antarctic ice shield for millions of years. A hole of 3,768 meters was drilled on February 5.
The drilling from the Russian Antarctic station Vostok under which the lake is situated started in 1990. The Academy of Sciences compared the event with the landing on Mars. Unknown forms of life may be found there.
Vostok water samples are being tested at the Arctic and Antarctic Research Institute, the St. Petersburg Nuclear Physics Institute and the Limnology Institute of the Russian Academy of Sciences in Irkutsk. Some samples may be shared with the Moscow Microbiology Institute.
The lake has been isolated from the atmosphere for several millions of years and no one knows what it may contain. Even if nothing but bacteria is found, that would be a breakthrough in science.