Is US military cloud safe from Russia?

A technology company bidding for a Pentagon contract to store sensitive data has close partnerships with a firm linked to a sanctioned Russian oligarch, the BBC has learned.

The Jedi project, a huge cyber-cloud which could ultimately store nuclear codes, has already sparked security fears.

Viktor Vekselberg, who is close to the Kremlin, has links to C5, a group of cyber-investment companies which has worked closely with the leading bidder, Amazon Web Services (AWS).

Both C5 and AWS say C5 is not involved in the Jedi bid in any way.

All bids for the cloud are sealed. The Pentagon refused to comment, stating that information about companies involved could not be disclosed.