Racing Point team boss Otmar Szafnauer has confirmed a sheared bolt within his power unit was the reason for Nico Hulkenberg’s non-start at the Formula 1 British Grand Prix.

Hulkenberg was set to start his first race since the Abu Dhabi Grand Prix in November last year but a broken part meant he was unable to take to the grid at Silverstone.

“It looks like a bolt sheared within the clutch housing and that bolt got caught and therefore wouldn’t allow the internal combustion engine to turn over. So where the bolt had fell off it got jammed and therefore we couldn’t turn the engine over,” Szafnaeur said.

“I think it’s a bit early to understand why but it did sheer off so it could be a material issue, it could be an over-torque issue.

“I don’t know, I’m sure all those bolts are torqued to a certain specification. Say the torque wrenches just aren’t right and you over-torque it, it could sheer it. It could be a material issue in manufacturing. But until you look into all those things: was the bolt brittle, was the material brittle? I don’t know. So we’ll have to understand the root cause and make sure that we fix it.”

Reflecting on his weekend, Hulkenberg felt the fact he was unable to start summed up a “crazy” weekend for the German.

“It's crazy, isn't it? Somehow it fits into all these crazy days that I've experienced,” Hulkenberg added. “But obviously disappointing for me and for the team.

“They tried everything, but [due to] some sort of power unit issue, we didn't manage to start the car and get out there, which is obviously a disappointing problem.

“If there's a next weekend, then today would have been very important to get more experience to understand and learn more about the car, especially in the race conditions.

“This is just lost on that side, but I guess it is what it is now. We'll have to see how things go for next weekend.”