Russia's prosecutor general on Monday said it had banned a foundation started by US film star George Clooney and his human rights lawyer wife Amal.

"The activities of The Clooney Foundation for Justice are declared undesirable on the territory of our country," it said in a statement.

The organisation "conducts extensive work aimed at discrediting Russia, actively supports false patriots and members of banned terrorist and extremist groups".

"Under the guise of humanitarian ideas, these 'warriors for justice'... advance initiatives of criminal probes against the highest Russian authorities," it said in the statement entitled "The Russian Prosecutor General's Office Appreciates Hollywood Activists' Acting Talent".

After Moscow sent troops into Ukraine in February 2022, Russian authorities have upped repression of dissent to levels not seen since the Soviet Union.

In July, the Clooney Foundation, along with several other non-governmental organisations, filed a case with the UN Human Rights Committee, accusing Russia of violating the human rights of Ukrainians killed in a 2022 missile attack on Vinnytsia.

In early August, Russia's prosecutor general banned as "undesirable" German pro-democracy foundation Konrad Adenauer and in July did the same with the Moscow Times news outlet.

The "undesirable" status forces organisations to shut down in Russia and means Russians that work for, fund or collaborate with them can also be liable to prosecution.