Champion Irish trainer Aidan O'Brien has put five horses into quarantine ahead of the Melbourne spring carnival.

O'Brien won last year's Cox Plate with the Coolmore-owned Adelaide but has not had a Melbourne Cup runner for seven years.

The stable's three Cup entrants - Kingfisher, Order Of St George and Bondi Beach - are among the five in quarantine with leviathan Australian owner Lloyd Williams buying recently buying shares in the trio.

Highland Reel and Ol' Man River are entered for the Cox Plate.

The first shipment of European carnival horses is due in Melbourne on Saturday to join the Japanese contenders at the Werribee quarantine centre.