Britain's media regulator Ofcom said Kremlin-backed Russian broadcaster RT had broken impartiality rules in news and current affairs programs aired in March and April, including coverage of the poisoning of former spy Sergei Skripal and his daughter Yulia.
"Taken together, the seven breaches represent a serious failure of compliance with our broadcasting rules," Ofcom said on Thursday. "We have told RT that we are minded to consider imposing a statutory sanction."
RT said it was "extremely disappointed" by Ofcom's conclusions and would decide its next steps shortly.
The channel, which is broadcast by TV-Novosti and funded by Russia's Federal Agency for Press and Media Communications, provides a Russian perspective on UK and global news and current affairs.
Ofcom said RT's mission was to make available an alternative point of view on world events, especially Russia-related ones, but RT recognized that did not require presenting a Russian point of view as if it were the only point of view.
But it said RT had failed to give sufficient weight to a range of views in seven current affairs discussion or news items.
Two cases involved discussions of the Skripal poisoning on current affairs program "Sputnik," co-presented by former British lawmaker George Galloway, it said.
Britain has accused Russia's GRU intelligence agency of trying to poison Skripal and his daughter with a nerve agent in the English city of Salisbury in March. Russia denies the allegations.
Other programs that Ofcom said broke the rules included a report on the Ukrainian government's position on Nazism and the treatment of Roma gypsies, which it said did not include sufficient challenge to criticism of the government, and four current affairs and news items on the Syrian conflict, which it said failed to include a range of viewpoints.
RT said the investigations into it were almost all initiated by the regulator.
"We operate under rules outlined by the regulator and always strive to abide by them," a spokesperson said.
"It appears Ofcom has failed to fully take on board what we said in response to its investigations and, in particular, has not paid due regard to the rights of a broadcaster and the audience."
Ofcom said it would consider further representations made by the licensee, and could impose sanctions ranging from broadcasting a statement of Ofcom's findings to a financial penalty and, in the most extreme cases, revoking a licence.