David Balland, a co-founder of French crypto firm Ledger, had his hand mutilated while he and his wife were kidnapped, the Paris prosecutor said, adding that 10 people were being questioned following the freeing of the pair.

A co-founder of French crypto company Ledger was released on Wednesday after being kidnapped from his home in France, the prosecutor's office in Paris said. David Balland was kidnapped early on Tuesday morning at his home in central France and taken by car to another address where he was held captive,