Victorian stewards have questioned a jockey regarding his alleged betting activities.

Australian jockeys are banned from betting on thoroughbred racing and stewards queried the rider after receiving a tip-off.

Racing Victoria's deputy chief steward Rob Montgomery refused to name the rider but said the probe centred on "small amounts" wagered on races.

Montgomery said the investigation was ongoing as stewards collated further information.

"We have interviewed people, including the rider in question and we have collated some evidence from various TABs," Montgomery said.

Montgomery said the jockey under investigation did not ride at Sandown on Wednesday.