YouTube has removed TalkRadio's channel from its platform.

The Google-owned service has not given an explanation for its action, but there is speculation that it relates to its rules on Covid-19-related misinformation.

Fact-checkers have repeatedly challenged some of the claims made by interviewees featured by the London-based radio station.

TalkRadio said it was seeking an explanation and defended its output.

"We urgently await a detailed response from Google/YouTube about the nature of the breach that has led to our channel being removed from its platform," it said in a statement posted to Twitter.

"TalkRadio is an Ofcom-licensed and regulated broadcaster, and has robust editorial controls in place, taking care to balance debate.

"We regularly interrogate government data and we have controls in place, use verifiable sources and give space to careful selection of voices and opinions."

For now, YouTube's only statement on the matter is a notification on what used to be TalkRadio's page on its platform.

"This account has been terminated for violating YouTube's Community Guidelines," it says.

The media watchdog Ofcom told the BBC: ""This was a decision for YouTube. Like other UK stations, TalkRadio's radio channel comes under our Broadcasting Code. When we assess programmes under our rules, we take account of a broadcaster's right to freedom of expression, and the right of listeners to receive information and ideas."

TalkRadio has about 424,000 listeners, according to the latest figures from market research provider Rajar.

It had used YouTube as a means to livestream shows from its studios and to provide an archive of past broadcasts.

It noted that it continued to stream its programmes via its own website as well as Facebook.

However, YouTube's action means that TalkRadio's website now features many articles featuring broken embedded clips, as do other outlets that embedded its material.

YouTube operates a "three strikes" policy, whereby channels that break its community guidelines three times within a 90-day period can be permanently banned, but other infractions lead to temporary restrictions.

The US firm has previously imposed a permanent ban against conspiracy theorist David Icke, and a one-week video suspension of right-wing outlet One America News Network's ability to publish new clips - in both cases for breaches of its Covid rules.

Digital rights campaign group Big Brother Watch likened the latest action to the kind of behaviour one would expect in China.

"YouTube's termination of a national broadcaster is further evidence that privatised, big tech censorship is spiralling out of control and must be challenged," its director Silkie Carlo told the BBC.

Social media sites have come under increasing pressure to tackle the rise of coronavirus falsehoods and conspiracies online - particularly about the vaccine and the latest wave of coronavirus.

But they face a number or dilemmas. Primarily, the battle between free speech and the need to tackle disinformation that has been linked to real-world harm.

Drawing a line between what counts as legitimate concerns about lockdowns and false conspiracies about the pandemic can be tricky - especially when some of those views are carried by mainstream news outlets.

YouTube has previously taken action against influencers and groups who have shared popular, slick videos promoting false claims about the pandemic - but the action against TalkRadio's popular radio station marks a first, at least for the UK.

It remains unclear why TalkRadio's YouTube account was removed - but it has been controversial for its choice of speakers and discussions around the pandemic and lockdowns.

• Coronavirus pandemic