Experienced New Zealand jockey David Walker has been charged by the Racing Integrity Unit with betting on another horse in a race he was riding in at Palmerston North.

The RIU charged Walker with two breaches of the New Zealand rules of racing following his ride on Watch Your Man in race three at Awapuni on August 16.

In a statement, the RIU contends the 38-year-old placed bets on another horse, St Ransom, and deliberately rode his horse to ensure his bets were successful.

Under New Zealand's rules, a rider may only bet on the horse he is riding.

RIU general manager Mike Godber's recommendation that Walker's licence be suspended was acted on by New Zealand Thoroughbred Racing on Thursday.

"The allegations before Mr Walker are serious and threaten the very fabric of thoroughbred racing," Godber said in a statement.

The investigation is ongoing but NZTR chief executive Greg Purcell says a suspension is warranted until a Judicial Control Authority hears Walker's case.

"Given the seriousness of the allegations and the RIU's summary of evidence collected, NZTR is moving to suspend Mr Walker's licence to ride in races."

The suspension is effective from noon on Friday.

A date has not been set for the JCA hearing.