Red Bull Racing team boss Christian Horner described himself as "desperately frustrated" that a technical failure cost Sebastian Vettel victory in the Bahrain Grand Prix.
The German led the opening race of the season from pole position and maintained control of the race through the pit stop phase, only to fade away to fourth with a power loss that appeared to be related to an exhaust problem.
"Very annoying," Horner told BBC Sports. "We really had the race comfortably under control. It was frustrating to either have an exhaust failure or electrical issue that caused the power loss.
"Sebastian drove fantastically well to maintain fourth place which is still valuable points, but still desperately frustrating when the race had gone well, the strategy had gone well, we had covered the Ferraris and he was nursing his tires."
Horner added that the exhaust system on the RB6 was not significantly different from that which the team used in 2009 and remained speculative about the cause of Vettel's problem until the car was released from parc ferme.
"We don't at the moment know whether it's exhaust or something else because it was intermittent," he said. "We need to get the car back and understand it."