Ron Dennis has denied that Fernando Alonso received an electric shock from his MP4-30 resulting in last Sunday's crash.
The double World Champion spent three nights in a Spanish hospital following an accident on the final day of the second pre-season test.
Hitting the wall at the exit of Turn 3, in what Sebastian Vettel called a "strange" crash, rumours about what may have happened have been doing the rounds.
McLaren have already stated that the crash was "caused by the unpredictably gusty winds", however, that did little to quieten the whispers.
Holding a press conference at the Barcelona circuit on Thursday, he has now categorically denied the rumours.
"There was absolutely categorically no electrocution," said the McLaren CEO.
"In all the previous runs, Fernando was saying it was tricky because the wind is moving the car around. Our conclusions that it was related to the wind was based on his comments and the comments of a third party."
He later added: "We can categorically say he didn't suffer an electric shock. We can categorically say that, we believe, the car did not fail. Everything after that becomes subjective."
He did, however, reveal that Alonso was "unconscious in the car for a relatively short period of time.
"When he came to rest, all we know is that the radio was on and we could hear him breathing. There were no other noises. They say it was seconds."
This is what prompted medical staff to have Alonso airlifted to hospital.
The McLaren driver spent three nights under observation, as they "wanted to make sure everything was perfect."
He was released on Wednesday but McLaren immediately announced that he would not take part in this week's final Barcelona test.
Dennis, though, is confident he will be back on track at the season-opening Australian GP.
"I see no reason why he won't be racing in Australia," he said.
"There will be some tests and processes laid down in the FIA. I can't see any reason he won't just sail through it. It's not for me to determine."