Red Bull's engine supplier Renault has apologised to the team for the blown engine that cost Sebastian Vettel victory in the Korean Grand Prix.
Vettel led from the start of Sunday's Formula One race until 10 laps from the finish when his engine gave way.
Earlier, Mark Webber spun out of the race, meaning Red Bull finished without any points for the first time this season.
Webber slipped from leading the championship to second while Vettel fell from second to fourth on a day which team principal Christian Horner described as "cruel" and "appalling."
"Renault must apologise to the whole team for the engine failure on Seb's car," Renault's Fabrice Lom.
"We need to investigate more before giving more details about the failure - it was an engine that was at its third grand prix but it obviously wasn't expected. What a bad result for us, we scored no points after starting on the front row - it's a big disappointment.
"We are still in the battle for both Championships and we will continue to push very hard - we took a hit today, but we will bounce back stronger in Brazil."
