"We are seriously concerned about the US biological weapons activities in Richard Lugar Center for Public Health and Research in Georgia's Alexeyevka," Karasin said.
The official added that Moscow was still expecting explanations from Washington and Tbilisi on the true nature of the lab's activities, conducted close to the Russian border.
READ MORE: Georgia Ready to Allow Russian Experts to Inspect Lugar Center
In September, former Georgian Minister of State Security Igor Giorgadze said the US-funded Richard Lugar Center for Public Health and Research in Georgia might have carried out lethal experiments on Hepatitis C patients. Giorgadze said he had information that 30 individuals had died in December 2015, and 43 more in April and August of 2016, all after being given treatment at the laboratory, with the causes of the deaths unconfirmed.
In October, the Russian Defense Ministry said that the Pentagon was using laboratories in Georgia, including the one at the Lugar Center, to research ways to deliver and unleash biological weapons agents in breach of international accords.
Georgia and the United States have both dismissed the accusations.