Markets on many of the Jewels were suspended last night after leading trainers Mark Purdon and Natalie Rasmussen advised the Racing Integrity Unit of their concerns over possible contamination for nine of their starters on Saturday.

The Racing Integrity Unit will now take samples from all nine horses involved in an attempt to clear them of any accidental exposure to prohibited substances before tomorrow.

Nobody involved would confirm the exact nature of the contamination concerns, but the Herald understands the testing is precautionary.

The TAB suspended the markets for most of the Jewels races as soon as they were informed and they could stay closed until tonight but it seems unlikely the tests will result in any scratchings or dramatic changes to the meeting.