Flavio Briatore has denied that Fernando Alonso had health issues before his Barcelona accident, but has admitted the Spaniard "crashed without any apparent reason".
Double World Champion Alonso will miss this weekend's opening race in Australia after doctors advised him to skip the grand prix after he suffered concussion during his shunt on the final day of the second test on 22 February.
There have been plenty of question marks over the circumstances surrounding the accident with some saying he wasn't feeling well before the incident while others claim he blacked out.
McLaren have dismissed the reports and Briatore, Alonso's manager, has also insisted that medical tests after the accident shows he was in fine health.
"If Fernando had had a problem, a heart problem, a small stroke, a blood clot; it can happen even to a great sportsman," Briatore told Sky Italia.
"And we have seen that absolutely all the examinations and tests made on the driver were negative."
He added: "If Fernando had had problems, the doctors would have discovered them. If he had passed out briefly, they would have seen. We did hours of tests with the leading specialists in Europe."
As for the accident itself, Alonso's MP4-30 crashed into the wall after Turn 3 at the Circuit de Barcelona-Catalunya and Briatore admits he is none the wiser after viewing footage of the incident.
"I saw footage, which Bernie Ecclestone sent me, where we see that the impact is not so hard. [Ferrari's Sebastian] Vettel is behind, he passes, and you see Fernando crashes without any apparent reason," he said.
"We have to see if there is a steering problem. We have not had any information on that from McLaren.
"The accident, if you see it, you do not say: 'Mamma mia, what a crash.' It is the sort of accident you see all the time.
"The angle in which the car hit the wall could have been bad for Fernando. The impact was hard."
There have also been reports that Alonso suffered electric shock, but Briatore is waiting for the FIA report on the issue.
"The FIA is investigating the accident. I hope not, but if there was an electrical problem they must say because it could happen to other drivers. We have to know what has happened for everybody's peace of mind.
"But you all know that there is a cut-off [in the electrical safety system]; it was closed for Fernando."