France's national fraud prosecution unit has opened an investigation for “corruption” over a French firm's security contract signed with Russian oligarch Iskander Makhmudov, and negotiated by Alexandre Benalla while the latter was a security aide at the Élysée. Mediapart first revealed details of this contract, which involves a company run by Benalla's friend Vincent Crase, back in December. In a separate development the French prime minister's head of security has resigned after claims that her flat was used to host a bail-breaching meeting between Benalla and Crase that was secretly recorded in July 2018. She denies any wrong doing. Fabrice Arfi, Antton Rouget and Marine Turchi report.