The man was checked by border guards on the train at Base-Mulhouse on Thursday morning and found to have more than 3,500 notes of 500-euro denomination in his bag.

The sum is the largest amount of cash sized in cash by authorities in France so far this year, said Le Matin in a report sourced from AFP and Tamedia’s Newsnet.

The man appeared on Saturday before a special prosecutor dedicated to inter-regional affairs (JIRS) in the French city of Nancy.

From the initial findings of the investigation the case appears to be one of tax fraud, Rémi Coutin, deputy prosecutor for JIRS is quoted as saying.

“Other people of Spanish nationality deposited money in a Swiss bank that they had to retrieve,” Coutin said.

“The suspect is a courier responsible for repatriating the money in Spain,” he said.