Melbourne jockey Mark Zahra has been suspended for 12 days after pleading guilty to causing interference in the Grand Prix Stakes at Doomben.

Stewards found Zahra's mount Harvard moved in and caused interference to Glen Colless on Last Typhoon on Saturday.

Zahra said he had shifted but immediately pulled his mount clear.

Chief steward Alan Reardon said he accepted Zahra had tried to correct the problem but it was clear interference.

Zahra rode Azkadellia in the Doomben 10,000 but he has not been confirmed for the ride in the Stradbroke Handicap on June 11.

In an inquiry into the riding tactics employed in the Doomben 10,000, stewards accepted the explanations of Jim Byrne, Zac Purton and Paul King.