Dubbo trainer Clint Lundholm had an afternoon he would rather forget after being questioned by stewards at Rosehill over three tubes of paste found in his float.

Lundholm, who had three runners at Saturday's meeting, initially told stewards he had borrowed the float and assured them the pastes had not been used on his horses.

His explanation was accepted and his two Highway Handicap entrants allowed to run, both finishing unplaced.

Chief stipe Marc van Gestel later summoned a rattled Lundholm back to the stewards' room, informing him at least one of the tubes appeared to have been recently used.

A subsequent phone call to his parents-in-law, who lent him the float, had also revealed the truck had not been used in months before he borrowed it.

Van Gestel again asked Lundholm if he had used the paste on his horses since leaving Dubbo, adding that the substance was not illegal.

The trainer admitted he had administered the paste on Friday.

He apologised to stewards and said he was worried because he did not fully understand the treatment rules.

"To be caught with them in my float and be put under pressure, I panicked," Lundholm said.

The trainer's Rosehill runners were ordered to be swabbed and the inquiry has been adjourned.