Jockey Beau Appo has been unsuccessful in an internal application into a four-week suspension for weighing in light on a winner at Toowoomba.

Appo rode Pieridae who won the last race at Toowoomba on April 22.

He was suspended for four weeks and the horse disqualified after Appo weighed in 0.8kg light.

Appo sought an internal review on the grounds he was not responsible as he claimed he had weighed out correctly.

He argued a gel pad used to make up the weight may have later come off the saddle packing.

Internal reviewer Kane Ashby dismissed the application after listing lengthy efforts to find the gel pack or any evidence of it coming unattached to the saddle had failed.

There have been several cases of jockeys weighing in light across Australia in recent years with the latest in Cairns on Monday.

Trainer Roy Chillemi was fined $1000 after accidentally leaving the lead bag off winner Lord Archer who was disqualified.