Italian rider Dario Frigo was arrested before Wednesday's 11th stage of the Tour de France after doping products were found in his wife's car.
Frigo was arrested because his wife had the banned drug EPO in her car
Customs officials and local police arrested his wife on Tuesday with about 10 doses of the endurance-boosting drug EPO (erythropoietin).
A spokesman for the Fassa Bortolo team said Frigo had been arrested at 0630 BST and held for questioning.
Frigo, 31, was lying 52nd overall in the Tour this year.
He was forced to pull out of the 2001 Giro d'Italia when Italian police found drugs in his hotel room.
On Tuesday Russian rider Yevgeni Petrov was thrown out of the Tour after failing a blood test.
Doping teams have tested 129 riders since the Tour started 12 days ago.
Frigo's arrest has echoes of a similar case in 2002, when the wife of Lithuanian rider Raimondas Rumsas was arrested by French customes officers with drugs in her car.
Rumsas and his wife are to face a trial in France in November.