Audi called for further investigation

The officials declared the results of Sunday's race at Zandvoort provisional after suspicions were raised by the manner in which Mattias Ekstrom caught and passed his Audi team-mates Martin Tomczyk, Alexandre Premat and Oliver Jarvis in the closing stages.

All of the drivers and team members involved were interviewed about the situation following the race, and the DMSB has spent the past few days analysing the data at its disposal.

However, a verdict has been delayed as the officials want to speak to the drivers and Audi teams again. AUTOSPORT understands that the DMSB wants to hold more discussions because it has found something that that doesn't correlate with the story presented by Audi last Sunday.

Rather than force everyone involved to go to the DMSB's base in Frankfurt, it has been decided that further interviews will take place on the Friday before the race weekend at Oschersleben.

The DMSB has also confirmed that a decision will be announced before qualifying for the fifth round of the season that gets underway on August 1.

Team orders have been banned in the DTM since the end of the 2007 season, and Audi has denied that any of the drivers were told to slow down to aid Ekstrom's title bid, instead claiming that the Swede was so much faster than his team-mates because he had much fresher tyres due to a late final pitstop.

Part of Audi's defence included data comparing its drivers' lap times with that of race winner Gary Paffett, as his pace also dropped dramatically at the end of the race. However, the 2005 champion claimed that he was backing off simply to save his car, rather than because of any problems.

"I was coasting at the end - just saving the tyres," he said. "I backed off at around 1.5 seconds per lap and the gap was still getting bigger behind me."

Audi also raised suspicions by reportedly blocking its team radio communication to German broadcaster ARD for the final 10 laps of the race. However, the DMSB has since had access to all of the team's radio transmissions, along with data that includes speed, throttle and brake traces.