Racing Victoria stewards have adjourned an inquiry after jockey Ryan Maloney was stood down from his riding engagements at Caulfield.

Maloney admitted to stewards of taking duromine, a banned substance, when called upon to provide a random urine sample before Saturday's meeting.

Stewards told the jockey he was also stood down from future riding engagements, including Mornington on Sunday and Sandown on Monday, until the sample he provided is analysed and the inquiry is conducted.

He was further informed he needs to provide a clear sample and a medical certificate before being allowed to ride a horse again.

Maloney had a good book of six rides at Caulfield on Saturday including the well supported favourite Theanswermyfriend in the Group Three Victoria Handicap which weakened to finish last after leading under replacement rider Ben Melham.