Fernando Alonso's manager says reports the McLaren driver thought he was still a go-kart racer after being knocked out in a testing crash are "nonsense".
Alonso will miss the season-opening grand prix in Australia on Sunday as a result of the incident in Barcelona.
Flavio Briatore claims the stories originated in Spain.
"Everyone else wrote about it because it was almost funny," said the Italian, admitting that the crash was "very strange".
Briatore said Alonso had "lost some memory" for "two or three days" but insisted the two-time world champion had not suffered long-lasting injury.
"If Fernando had had problems, the doctors would have discovered them," said Briatore.
"If he had passed out briefly, they would have seen. We did hours of tests with the leading specialists in Europe."
In an interview with Sky Italia, Briatore said:
- All medical tests on Alonso for health problems were negative
- Reports that he had woken up from the crash thinking he was a 14-year-old kart racer were incorrect
- McLaren had given Alonso no information about whether the car had a steering problem
- McLaren's communications on the accident were "not brilliant"
- Alonso is "confident" about the quality of the McLaren car, despite major reliability problems during pre-season testing.
Briatore, who has not been involved directly in F1 since being found guilty of involvement in Renault's attempt to fix the 2008 Singapore Grand Prix, said he had seen video of the accident.
"The impact was not so hard," he said. "He crashes without any reason. We have to see if there was a steering problem."
McLaren have already said they have found no evidence that Alonso's car suffered any kind of mechanical failure following the crash at Turn Three of Spain's Circuit de Barcelona-Catalunya on 22 February, or that there was any irregularity in the energy recovery system.
Briatore described the decision by doctors to advise Alonso to miss the first race in Australia this weekend to avoid the risk of a potentially dangerous second concussion as "logical".
Reacting to speculation that Alonso suffered an electric shock, causing him to crash, Briatore responded: "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."