Toowoomba trainer Mark Currie has been suspended after Queensland Racing Integrity Commission stewards charged him with 16 counts relating to race day treatment.

Currie is a licensed trainer but often works as stable foreman for his son Ben who is the state's leading trainer on winners.

Stewards interviewed Mark and Ben Currie after opening an inquiry into activities at the stables on April 7, the day of the Listed Weetwood Handicap at Toowoomba.

Two of Ben Currie's stable staff have been stood down pending further inquiries.

At a resumed inquiry, Mark Currie gave further evidence regarding alleged breaches concerning race day treatment of horses at Ben Currie's Toowoomba stable.

QRIC Commissioner Ross Barnett said on Friday Mark Currie had been charged with 12 counts of race day treatment and four counts of improper practice.

Barnett said Currie had entered a plea of not guilty and the matters have been adjourned for hearing on a date to be fixed.

He said Currie had his licence suspended until the matters were determined.

Barnett said QRIC would allege the offences occurred on two separate occasions on the morning on April 7.

"The treatment allegedly occurred pre-dawn that morning and the second was the suspicious activity the QRIC Integrity Investigations Team members witnessed while monitoring the premises," Barnett said.

"It was also alleged that race day treatment occurred at the same stables before Ben Currie-trained horses were transported to race at Doomben and Gatton on March 24."

Barnett said inquiries into the possible involvement of other people were continuing.

"Today's outcome is not the end of the investigation. The focus of these continuing and protracted enquiries is the involvement of other racing industry participants and the outcome may not be known for several weeks," he said.

"I expect further disciplinary action may be taken as QRIC continues to analyse items seized from the stables including CCTV, saliva, urine and blood samples and phone records."