Russia's state-run broadcaster RT broke Britain's broadcasting code in its reporting about the March poisoning of a Russian former spy in England, Britain's media regulator says.
Ofcom said on December 20 that RT broke impartiality rules in seven programs broadcast over a six-week period in March-April, calling them "a serious failure of compliance."
It said the TV station failed to give due weight to a wide range of voices on a matter of major political controversy.
The watchdog said it was considering a "statutory sanction," which could range from a fine to a license suspension.
RT said it was "extremely disappointed by Ofcom's conclusions."
Britain blames the Russian government for the poisoning of Russian former double agent Sergei Skripal and his daughter, Yulia, in the city of Salisbury.
Russia has repeatedly denied evidence that its agents were behind the poisoning and accused British intelligence agencies of staging the incident to stoke anti-Russian hysteria.
The Skripals survived the poisoning, in which a Soviet-made military nerve agent known as Novichok was used.
Two other British citizens were exposed to the same nerve agent in June, apparently by accident; one of them, Dawn Sturgess, died.
Ofcom since 2012 has repeatedly found RT to have breached its rules on impartiality and of broadcasting "materially misleading" content.