PARIS: France has arrested more than 20 people over two recent kidnapping plots targeting crypto traders in Paris and another attempt in western France, a source close to the case said Tuesday, asking not to be named.

The arrests are part of an investigation by France’s organised crime office into the May 1 abduction of a crypto-millionaire’s father who was later rescued by French police, the May 13 attempted kidnapping this month of a French cryptocurrency entrepreneur’s daughter and grandson, and a new plot that was foiled Monday near the western city of Nantes, the source said.

The incidents have raised concerns about the security of wealthy crypto-tycoons who have notched up immense fortunes from the booming business.

The arrests of groups of suspects were made on different occasions over the last month and not simultaneously. The two Paris plots were revealed at the time but this is the first time details of the incident outside Nantes have emerged.

According to the source, six people have been charged in connection with the May 1 kidnapping in Paris of the father of a man who made his fortune in cryptocurrency.

The victim, for whom a ransom of several million euros was demanded by his captors, was freed during a raid on May 3 by the security forces on a house in the Essonne region outside Paris where he was being held.

The victim was abducted in front of witnesses by four hooded men who bundled him into a delivery van and injured him.

A few days later, on May 13, the daughter and grandson of the chief executive of a cryptocurrency company escaped a street kidnapping in Paris, an incident that received wide coverage as dramatic images were posted on social media.

The entire team of aggressors involved in that plot were arrested, said the source, without giving further details on the number of people involved.