Ericsson and Kirkwood were demoted to 31st and 32nd in the results after it was found that the #27 and #28 cars were in breach of the regulations.

IndyCar found modifications to the Dallara-supplied Energy Management System (EMS) covers and cover-to-A-arm mounting points with unapproved spacers and parts.

IndyCar said the modifications provided the capability for an aerodynamic benefit.

The parts must be run as supplied by Dallara, the official chassis partner for IndyCar.

Each car was it with a 100,000 USD (155,000 AUD) fine and had its respective team or competition manager suspended for one race.

“After careful analysis with IndyCar surrounding the Indianapolis 500 post-race technical violations and penalties to the Nos. 27 and 28 cars, we accept the penalties issued and will not pursue further review,” Andretti Global said in a statement.

“While we are disappointed in the outcome, we will take the necessary steps to ensure full compliance moving forward and want to thank our fans, crews and sponsors who continue to support us.

“Our focus now shifts to the future and delivering strong, competitive results on track — beginning this weekend with the Detroit Grand Prix.”

Prema Racing was the other team stung by a post-race penalty.

Callum Ilott in the #93 was demoted to last for failing to meet the minimum endplate height and location specification. It accepted the penalties in the immediate aftermath of them coming to light.

IndyCar returns on June 2 (AEST) for the Detroit Grand Prix.