Britain's broadcasting watchdog on Wednesday opened seven impartiality probes concerning Russia's RT news channel, noting "a significant increase" in programmes warranting investigation since the poisoning of a former Russian spy in March.
"Ofcom has today opened seven new investigations into the due impartiality of news and current affairs programmes on the RT news channel," the regulator said in a statement.
Ofcom added that TV Novosti, the holder of RT's UK broadcast licences, which is financed from the budget of the Russian Federation, had an overall compliance record not "materially out of line with other broadcasters."
"However, since the events in Salisbury, we have observed a significant increase in the number of programmes on the RT service that we consider warrant investigation as potential breaches of the Ofcom Broadcasting Code," it said.
Former double agent Sergei Skripal and his daughter Yulia were poisoned in the English city of Salisbury last month, sparking a bitter diplomatic crisis between Moscow and London, which says a nerve agent developed in Russia was used on the pair.
Russia strongly denies involvement in the attack, which sparked a flurry of expulsions of diplomats on all sides.
RT provides a Russian perspective on British and global news and has an average audience of 3,400 viewers at any given point during the day.
In a statement the news channel said its prior compliance record put "to bed any of the salacious political statements and challenges made against our channel".
"Our editorial approach has not changed since the events in Salisbury, and we will be directly addressing this matter with the regulator."
- Licence threat -
The investigations centre on programmes broadcast between March 17 and April 16, following the March 4 attack.
Ofcom has the power to impose financial penalties, or even revoke the licence to broadcast if a "high" threshold is met.
"The previous cases in which we have determined that a licensee is not fit and proper to hold a licence have involved the broadcast of hardcore pornography, which represents a serious risk to children, and the broadcast of material likely to incite terrorist crimes."
RT was set up in the mid-2000s to counter what Russian President Vladimir Putin saw as the dominance of American and British international media organisations and their allegedly pro-Western bias.
The channel is seen by its critics as giving a platform to conspiracy theorists as well as far-right or anti-establishment figures who emphasise Western hypocrisy or corruption.
Several British MPs have called for a ban on RT.
Speaking last month, Labour MP Phil Wilson said British politicians should refuse to be interviewed by the channel, where former Scottish First Minister Alex Salmond has a talk show.
"It is a propaganda mouthpiece for the Russian state and should not be engaged with by any democratic politicians," Wilson said.
The channel responded at the time by saying it was being used as a "political pawn" and Britain was in danger of "doing away with any concept of press freedom".