Moussa S, as the French press are calling him, 23, managed to avoid being arrested at the end of July by hiding at his parents’ house.

But he finally gave himself up this week, charged with fraud in an organised gang, and helped complete the bigger picture for police.

Moussa S is suspected of having supplied a stolen cheque for €1 million to one Fabrice B, who used the money to buy a rare Burmese ruby of more than five carats in June last year.

The police were alerted a few days after the purchase, when the man from whom the cheque was stolen realised a large, unauthorised sum had gone missing from his account.

Fabrice B, who was living in the third arrondissement of Paris at the time, was quickly identified but could not be tracked down – he had disappeared along with the ruby.

He was eventually arrested and questioned, when he put police onto Moussa S.

But the ruby was never found.

“The supplier of this cheque, who also went by the name of Moise, has indicated that it was given to him by someone called Mac,” a source close to the affair told Le Parisien.

“He claims he did not receive any commission for selling the cheque.”

The plot thickened when police discovered the cheque used to buy the ruby one of 600 that had been stolen from BNP-Parisbas in November 2010.