LONDON: British Foreign Secretary Dominic Raab said on Sunday he was "absolutely confident" in allegations by the UK and its allies that Russia targeted labs conducting coronavirus research, branding the behaviour "outrageous and reprehensible".

Britain, the United States and Canada on Thursday accused a hacking group called APT29 of spearheading the online attacks on various organisations involved in Covid-19 vaccine development.

They said the collective is "almost certainly" linked to Russian intelligence, and intended to steal information and intellectual property.

Moscow quickly rejected the accusations as "groundless", and its ambassador to London said in a British television interview Sunday the claims made "no sense".

However, Raab reiterated that the trio's conclusions were based on assessments by Britain's National Cyber Security Centre (NCSC) and its counterparts in the US and Canada.

"We're absolutely confident that the Russian intelligence agencies were engaged in a cyber attack on research and development efforts in organisations in this country and internationally with a view either to sabotage or to profit," he told Sky News.

"At the time that the world has come together to try and tackle Covid-19... I think it's outrageous and reprehensible that the Russian government is engaged in this activity."

However Andrei Kelin, who was appointed Moscow's top envoy in Britain last November, ridiculed the claims in a BBC interview.

"I don't believe in this story at all, there is no sense in it," he told the Andrew Marr Show, adding he had learned about the hacking collective's existence from British media reports.

"In this world, to attribute any kind of computer hackers to any country, it is impossible."