Penske IndyCars are powered by Chevrolet engines, supplied in a partnership with Ilmor Engineering, raising questions as to who may have known what before the illegality of its push-to-pass system was unwittingly uncovered in the Long Beach Warm Up session.

“We respect the decision and actions of IndyCar as well as Team Penske’s commitment to improve their processes and controls,” said Reuss via a statement issued to media.

“Chevrolet engaged a third-party law firm to conduct a thorough review of the matter, and they found no evidence that any Chevrolet employee had any knowledge of or involvement in the matter.

“Chevy looks forward to engaging with IndyCar and our partner race teams to assist in any enhancements that further support the integrity of IndyCar competition.”

Josef Newgarden and Scott McLaughlin, who took the chequered flag first and third respectively at St Petersburg, were disqualified from that race.

The only sporting penalty incurred by Will Power was the loss of 10 series points because, while his car was illegal, he did not use the push-to-pass system at an illegal time.

That penalty netted out at just two series points given the disqualifications of his team-mates meant Car #12 rose to second from fourth in the official classification.

Rival team owner Michael Andretti has since said that he would have dismissed someone had such a breach occurred within his IndyCar operation without his knowledge.