Two international trackwork riders have been banned for returning positive drug tests in Victoria.

Frenchmen Pierre Boudvillain and Enzo Mezenguel were banned for two months and six weeks respectively after pleading guilty to having a banned substance in their system.

Stewards did not name the substance, charging the pair under AR81A, which covers alcohol and other drugs.

The pair were tested during trackwork at Ballarat on June 26 and were stood down on July 6.

Both will be required to return negative drug tests before they can resume handling horses.