Problems continue to dog trainer Ben Currie after stewards disqualified the last winner at Toowoomba, Pieridae, when his jockey weighed in light.

The Currie trained Pieridae led all the way to win Monday's Class Three Handicap (1210m) which was also the last leg of the quadrella and treble.

However, jockey Beau Appo was 0.8 kg under the handicapped weight and stewards disqualified the horse

The Les Ross-trained Reef Knot who was originally second was elevated to first.

Ross was on his way to Cunnamulla in western Queensland where he is guest speaker at a sportsman's dinner on Wednesday night.

In an ironic twist Ross was the last trainer to lose a Queensland race when one of his horses weighed in light after a race at Beaudesert in 2014.

"I am speaking at the dinner to mark 31 years to the day I started training and it shows every time you go to the races you never know what will happen," he said.

Chief steward Peter Chadwick said an inquiry had been opened into the reasons for the offence.

Currie faces a stewards inquiry on other matters this week and has also been asked to provide a reply to a Racing Queensland decision to consider rejecting his nominations.