Red Bull boss Christian Horner has revealed the freak cause of Daniel Ricciardo’s grid penalty at the Brazilian Grand Prix for changing his turbocharger following his retirement from the Mexican Grand Prix with the finger pointed at an eagle-eyed track marshal.

The Australian driver endured his sixth mechanical retirement across the last 11 Formula 1 races when was forced out with a suspected hydraulics issue.

Singapore V4, F1,

But starting the Brazilian Grand Prix weekend it was confirmed Ricciardo would serve a five-place grid penalty for taking on a new turbocharger – exceeding the permitted number of the unit for the season.

Following a full investigation into the issue, Horner has revealed the Australian driver’s Mexican GP turbocharger was effectively written off during his retirement from the race when a fire marshal spotted his car smoking and duly squirted extinguisher foam on the car.

Horner confirmed the unit was beyond repair and as F1 rules stipulate the team had to take the penalty to add further pain to a frustrating end to the season for Ricciardo.

“You can’t really blame them as the car was obviously smoking but they shot foam up the exhaust and as it solidifies in the turbo it terminated it,” Horner told Sky Sports F1. “He’ll take a five-place penalty but hopefully on a track like this it is not actually that big of a penalty.”

Since claiming victory at the Monaco Grand Prix while battling mechanical issues with his engine, Ricciardo has suffered six mechanical DNFs and has duly failed to reach the podium since his Monte Carlo triumph. Ricciardo also suffered a mechanical problem midway through Q2 of qualifying at the Japanese round which restrained him to 15th on the starting grid.