A disgraced former policeman with links to French President Emmanuel Macron was taken into custody Tuesday in a corruption probe involving alleged business ties with a Russian oligarch, sources told AFP.

Vincent Crase lost his job last year after he and a friend, Alexandre Benalla -- a former top security aide to Macron -- were filmed roughing up protesters during a May Day demonstration.

Crase, former security head of Macron's LREM party, is suspected of having been involved in outside security work while employed as a government official.

The Mediapart news site has reported that investigators were looking into links between Crase's security firm, Mars, and Russian oligarch Iskander Makhmudov, reputed to be close to Russian leader Vladimir Putin.

Mediapart said officials were investigating payment by Makhmudov for the protection of his assets in France and Monaco.

A source told AFP Tuesday that Crase had been questioned by economic crimes investigators on Makhmudov's activities.

Crase has denied the charges, and said he has never met Makhmudov.

His lawyer, Christian Saint-Palais, declined to comment on Tuesday.

Revelations that Macron's office had known about Benalla and Crase roughing up demonstrators but attempted to cover it up, led to an outcry by political opponents.

Benalla has since been charged with illegally using diplomatic passports he was given when working at the Elysee.