Racing NSW stewards have set a date for the resumption of their inquiry into a positive swab returned by a John McNair-trained horse.

Normandy tested positive to a metabolite of methamphetamine, commonly given the street name Ice, at Newcastle on March 18.

Stewards adjourned their initial investigation last month to check telephone records after a man who made an anonymous call to Racing NSW on the day of the positive swab emerged as a person of interest in the case.

McNair, the trainer of former top sprinter Hay List, has denied giving the horse any treatment.

The inquiry will resume on July 27.