Bosses at the Autodromo Nazionale Monza are facing an investigation as claims they were aware of problems with the track surface before the World Superbike Championship round continue to grow.

The high-speed Italian circuit hosted the fourth round of the WSBK season in May, but tyre concerns and poor weather contributed to one race being abandoned and the other stopped after just eight laps.

However, unrelated problems with the track surface even before the event got underway have since been revealed, with Gazzetta dello Sport stating that local investigators are looking into claims circuit officials were aware of the asphalt 'bubbling', thus providing a reduced level of grip

It is a claim that is now being supported by Marco Melandri, who crashed at the end of the opening lap of the WSBK race as he exited Parabolica.

At the time it was assumed the impending rain (which began falling heavily on lap three) contributed to his fall, but the Italian insists there were no wet patches on the circuit at the time. With this in mind, he is now certain that the poor asphalt was to blame for him falling.

"That's why I crashed! I couldn't explain it to myself. I was angry and thinking that I missed seeing a damp patch during the warm-up lap," he told "It was at the end of lap one. I think the sun was out. Anyway, I'm certain that in that moment it wasn't raining and there weren't any visible damp patches.

"I was on the racing line at the turn and I had just starting re-opening the throttle, when I realised that the bike was sliding more than normal, but it was already too late to control it. I repeat, in front of me I had a clean line and no patches. I think that the relationship between the presence of the bubbles and the crashes can't and should not be ruled out."

Enrico Ferrari, the general director of Monza, has now told Gazetta dello Sport that he didn't raise the issue in the days leading to the race as he didn't want to create 'false alarms', adding that it hasn't been proven that the track condition contributed to the accidents.

David Salom, Sergio Gadea and John Hopkins were also casualties in the opening laps of the Monza race, though it isn't certain whether the weather or the track surface were contributing factors to the accidents.