Walkinshaw Andretti United’s Chaz Mostert has been disqualified from Race 16 at Hidden Valley Raceway for a technical breach.

The #25 Mobil 1 Optus Racing driver finished the first 38-lap affair at the Merlin Darwin Triple Crown in fourth behind Anton De Pasquale, Will Davison, and Shane van Gisbergen.

Following the opening encounter, it was alluded to on the Supercars broadcast that Mostert was facing an investigation for a pre-race breach.

In the wake of a hearing at the conclusion of Saturday’s play, the stewards pinged Mostert for having a battery-operated air blower inserted in the front bumper on the grid for the commencement of Race 16.

The stewards’ summary read: “Rule D8.1.8 prohibits the use of any device to artificially vary the temperature of any part of the Car when it is on the Grid with the exception of Driver cooling. The HoM observed a battery-operated blower inserted in a cavity in the front bumper of Car 25 when it was on the Grid for Race 16.

“The device was activated. It was blowing air onto the radiator of Car 25. The Authorised Representative did not dispute that the device had the effect of lowering the temperature of the engine cooling system on Car 25 from the temperature build-up achieved on the reconnaissance Lap and that, as a result, Car 25 had an advantage over other Cars at the start of Race 16. The Authorised Representative acknowledged that Rule D8.1.8 was breached.

“The Authorised Representative explained that the device had been used by a member of the Team without consulting him and without his knowledge. He explained that the Driver had reported an issue with the Car on the reconnaissance Lap and that he had been occupied attempting to identify and resolve that issue.

“While the Stewards accept that the breach was not deliberate, it nonetheless represents a technical infringement for which the universal Penalty is Disqualification. Given that in this case the breach resulted in a potential sporting advantage for Car 25 at the start of Race 16, the Stewards are satisfied that no other Penalty would be appropriate in this case.

The stewards’ report also read: “The Competitor is reminded that Decisions and Penalties that may be subject to Appeal are set out in B7.7.2 and the Rights to and process for an Appeal are set out in B5.”

The disqualification comes just a day after being scratched from Practice 2 for a tyre pressure breach.

As a result, Mostert loses the 80 points he earned in Race 16. However, he has retained fifth in the drivers’ championship.

The disqualification also means Brad Jones Racing’s Andre Heimgartner is promoted to fourth and Mark Winterbottom of Team 18 to fifth.

Scott Pye, Cameron Waters, Broc Feeney, James Courtney, and Brodie Kostecki fill sixth through to 10th.