Brisbane trainer Brad Smith has again failed to attend an inquiry after telling stewards he had a medical condition.

Smith was suspended last month after failing to attend other inquiries on medical grounds.

"The matters concern a possible breach of AR 175 which relates to penalising any person who, in stewards' opinion, has been guilty of any dishonest, corrupt, fraudulent, improper or dishonourable action or practice in connection with racing," Queensland Racing Integrity Commissioner Ross Barnett said.

He said at his stage no further details of the allegations could be given.

Barnett said Smith remained suspended from training pending the outcome of an inquiry.

"Smith has applied for a stay which will be heard in the Queensland Civil and Administrative Tribunal on Friday afternoon," Barnett said.

Barnett said the commission was also dealing with a man who ran on to the track at Eagle Farm during a race.

The Brisbane man ran across the straight at the 200m mark during the last race on May 27.

Barnett said stewards wrote to the man giving him notice he had 21 days to give reasons why he should not be banned from all future meetings.