A Queensland cadet steward alleged to have mishandled a swab document has resigned.

The Queensland Racing Integrity Commissioner Ross Barnett said the cadet steward was suspended with pay last week pending the finalisation of an investigation into a complaint.

"The cadet steward was alleged to have deliberately entered false information on a chain of custody document which travels with race day samples sent to the QRIC Racing Science Centre for analysis," Barnett said.

"A positive swab result can have dramatic penalties for trainers and the QRIC has a duty to racing industry participants to ensure that all samples are handled in strict accordance with the procedures that are laid down."

Barnett said he had accepted the cadet's resignation on Wednesday.

"The industry's trust and confidence in the system relies on the integrity of QRIC staff at every step in the chain and any deliberate subversion of that process I regard as a very serious matter," he said.

"In this case, no racing participant was affected."

The cadet steward was the fifth QRIC official either sacked, stood down or redeployed in the past seven months.