Russia's state communications regulator said on Thursday that the BBC had published material that propagated the ideas of a terrorist group and that it was investigating whether the British public broadcaster had broken Russian law.

"Checks are underway into whether the BBC's internet sites... comply with Russian law. To date, material has been uncovered which transmits the ideological principles of a terrorist group [quotes of the terrorist al-Baghdadi,]" the regulator said in a statement.

Abu Bakr al-Baghdadi is the leader of Islamic State, a terrorist organization banned in Russia.

"An investigation is underway into whether these materials are in compliance with the norms of Russian legislation," the regulator's statement said.