IndyCar officials were still awaiting the release of Dan Wheldon's shattered car so that it can be included in the investigation into his death in Las Vegas two weeks ago.
Gian Paolo Dallara, who heads the company that makes the IndyCar chassis, said the vehicle was still "confiscated" by authorities, delaying the inquiry into the fatal crash in the series' last race decider.
Dallara is eager to look at the remains of the car to help piece together the final moments of the two-time Indianapolis 500 winner as he piled into the 15-car crash that cost him his life.
"We know, like everyone saw on television, that the multiple collision was started by a car that slowed down," Dallara told the Italian motor magazine Autosprint. "It was not a major slow down; in fact it was not very considerable. At most it was by 10 or 20 percent.
"But at that speed of about 350kph (218mph), when you travel two or three abreast on the banking, even such a small speed reduction is enough to generate a multiple collision. And when wheels touch, the cars are thrown up in the air. It's fatal."
Experts from the FIA, Formula One's governing body, are expected to play some part in the investigation into Wheldon's death.
F1 drivers at the Indian Grand Prix will this weekend wear black armbands as a tribute.
Jenson Button, who grew up as a teenager with Wheldon as they raced karts together around Britain, will also wear Wheldon's logo on his helmet this weekend on the Buddh International Circuit in homage to a friend and rival.
Dallara was already under way with testing for his new IndyCar chassis, which will feature a closed rear wheel system that should prevent cars being catapulted into the air as Wheldon's was in Las Vegas.
In a sad coincidence, Wheldon was the chief test driver for the new car, scheduled to be introduced next season, and it will now be named the Dallara DW12 in his honor.
