Caloundra trainer David Vandyke has denied the illegal substance altrenogest has been administered to star galloper Alligator Blood who has returned an irregularity after winning the Magic Millions 3YO Guineas.

The Queensland Racing Integrity Commission on Wednesday released a statement saying Alligator Blood had returned a swab irregularity to altrenogest after the Guineas on January 11.

Alligator Blood has since won two races in Melbourne including the Group One Australian Guineas.

A QRIC spokesman said the gelding's B sample from Millions day would now be sent for interstate testing.

A result should be known next month.

The QRIC spokesman said there would be no further comment until after the B sample result was known.

Altrenogest, more commonly known as Regu-mate, is banned for use on male horses.

It is a hormone given to keep female horses from being in season, or if they are already pregnant, to keep them from losing the foal.

Vandyke issued a statement after the irregularity was made public.

"I was informed today that Alligator Blood has returned an irregularity to altrenogest after his win on January 11 at the Gold Coast," Vandyke said,

"There is a B sample under review. Altrenogest is a drug that has never been used to my knowledge on Alligator Blood or any male horse in our stable.

"It is used in our stable under the brand name Ovumate and is given to some female horses under our care with accurate records kept surrounding administration.

"Those records have been given to QRIC.

"We are in the process of reviewing our security and stable management."

Vandyke said he would make no further comment as he awaits the result of the B sample.