F1's drivers had asked F1 race director Charlie Whiting to get guarantees from Pirelli about the safety of its products for the high-speed Spa-Francorchamps track after Sebastian Vettel and Fernando Alonso were hit by failures on Friday.
There was some scepticism from drivers and teams that the problems had been caused by simple debris, amid questions about the structural durability of the tyres.
However, following a detailed look overnight at what happened to the tyres, and a thorough examination of the Spa track, Pirelli is now convinced that the failures were indeed caused by a piece of metal.
Whiting told the teams and drivers on Saturday morning that a single piece of steel - which is believed to have come off Kimi Raikkonen's Lotus car at Turn 13, the left-hander of the Fagnes chicane - was to blame for both incidents.
The shaped piece was found by Pirelli engineers in the run-off area at Turn 13 on Friday night.
AUTOSPORT can reveal that investigations have pointed towards the piece of metal coming off the Lotus at 3.05pm when he ran across the kerb at Turn 13.
Three minutes later, both Vettel and Alonso ran across the kerbs at that exact point - which is where they picked up the punctures.
Pirelli's belief that this metal was to blame is backed up by the fact that the hole in Vettel's tyre exactly matches the size of the piece of metal.
To confirm the fact that the tyre failures were caused by debris and not by structural issues, Pirelli also conducted detailed fatigue tests overnight on its tyres as a precautionary measure.
AUTOSPORT understands that these tests showed that no signs of fatigue were discovered.
In light of Pirelli's investigations, it is understood that Whiting wrote to the teams and the Grand Prix Drivers' Association (GPDA) on Saturday morning to say he is satisfied with the safety of the Pirelli tyres and that he believes no further action needs to be taken.