A report in The Wall Street Journal claimed that the program had been modified into a tool for espionage and used to search for terms like "top secret".
Well-known British security researcher Kevin Beaumont expressed scepticism about this claim, saying, "There's so much b***shit in the briefings being given to press. AV uploading every document with term "top secret" would fry networks."
There's so much bullshit in the briefings being given to press. AV uploading every document with term "top secret" would fry networks. https://t.co/tu171QCwG8— Kevin Beaumont ? (@GossiTheDog) 11 October 2017
Anti-virus programs are installed mostly on machines running Windows. They have access to the entire system and, during routine scans, often upload suspicious files to virus databases for further analysis.
"The Federal Office for Security in Information Technology does not currently have any knowledge that the process took place as described in the media report. The BSI is in contact with the American partner authorities," the agency said in a statement.
"A warning from the BSI before the use of Kaspersky products is currently not provided, since the BSI has no evidence of a malfunction of the company or weak points in the software."
Wednesday's WSJ report quoted "a former US official with knowledge of information gleaned in 2015 about how the software was used to search for American secrets" as saying: "There is no way, based on what the software was doing, that Kaspersky couldn’t have known about this."
A report in The Washington Post on Tuesday claimed that Israeli government information security professionals had found NSA hacking tools in Kaspersky Lab's system when it gained access to the company's servers in 2014.
And The New York Times claimed that Russian Government employees had used Kaspersky's anti-virus software to search for the code names of US intelligence programmes, while Israeli intelligence officials looked on.
The spate of stories about Kaspersky Lab have come in the wake of claims that Russia influenced the direction of the US presidential election in 2016. These allegations have been mounting since Donald Trump defeated Hillary Clinton in November last year.
Some observers say Kaspersky Lab has become collateral damage in the stoush between the US and Russian Governments.