Team Penske fire leaders after Indy 500 scandal
Team president Tim Cindric, managing director Ron Ruzewski and general manager Kyle Moyer were all dismissed on Wednesday.
"Nothing is more important than the integrity of our sport and our race teams. We have had organizational failures during the last two years, and we had to make necessary changes. I apologize to our fans, our partners and our organization for letting them down," team owner Roger Penske said in a statement.
The case is particularly grave given that Penske is also owner of the IndyCar Series and the Indianapolis 500 race and the track, the Indianapolis Motor Speedway.
No replacements have been put in place yet but the team said "further announcements" would be made later this week.
The infringements were discovered ahead of Sunday's final qualifying race.
The car of Josef Newgarden, who is seeking an unprecedented third straight Indy500 victory, and teammate Will Power were found to have an illegally modified spec part on their cars.
Those entries were moved to the rear of the field, starting 32nd and 33rd, respectively, for Sunday's race and each entry was fined $100,000 by IndyCar.
It is not the first issue to have impacted Penske -- last year at the season-opening race in St. Petersburg, Florida, Newgarden and Penske team-mate Scott McLaughlin were ruled to have been in violation of two 'Push to Pass' parameters and were disqualified from that event.
The discovery of the latest violations, which concerned modified attenuators, had led to strong criticism from other teams.
McLaren's Mexican driver Pato O'Ward had suggested that there were other cases relating to Team Penske as well as the two public infringements.
"These are the only two times that it's been public. But it hasn't been the only two times. There's been another two or three things that they've caught about them, IndyCar Tech, where they just received fines," he told Motorsport.com.
"But ultimately it's not a good look. It's not a good look at all. Whether it's become public or not. This one obviously was very public. But some of the other things are also performance enhancers. For the race cars, not for the drivers. Those were not public," he added.
IndyCar president J. Douglas Boles said before the firings that it was vital the series maintained its integrity.
"The positive momentum around the NTT IndyCar Series and the Indianapolis 500 has been on a steep crescendo over the last several months, and we want it to be clear that our intent is to maintain that momentum and discourage teams from putting IndyCar in positions where it calls into the integrity of our officiating and the levelness of the playing field," Boles said.