Local authorities are investigating organisers of the Italian Formula One Grand Prix at Monza.
Last month, the World Superbike races at the fabled circuit were cut short due to rain and ensuing crashes.
La Gazzetta dello Sport reports that local prosecutors are looking into whether the circuit was to blame for installing a sub-standard track surface.
It is believed rider Marco Melandri has already been interviewed by the investigators, who reportedly suspect the organisers knew the surface was not adequate.
Melandri had said after one of the May races: "There are different tarmacs on the track. While the new tarmac doesn't allow for the water to drain away, the old asphalt is different and dries up very quickly."
The Corriere della Sera newspaper said Monza's technical boss Stefano Tremolada exercised his right to remain silent.
We reported last month that Italy's finance police raided Monza amid suspicions of tax offences, false invoicing and other discrepancies in relation to Sias SpA, the circuit operator, between 2007 and 2012.