"Something does not add up" about Fernando Alonso's pre-season testing crash, according to former McLaren driver David Coulthard.
Alonso, 33, crashed in his McLaren during the second pre-season test in Barcelona last month, suffering concussion.
The Spaniard will miss next weekend's season-opening Australian Grand Prix.
"I think there is more to this than we are being told about at this time," said BBC F1 co-commentator Coulthard.
Former world champion Alonso is in his first year back at McLaren - the team he raced for in 2007 - after five years at Ferrari.
It is a move Coulthard described as "not a marriage" but of just "pure convenience".
The Woking-based team, who have not won a race since 2012, have endured a difficult pre-season, with reliability issues plaguing them throughout testing.
Alonso's crash, which happened on the final day of the second test at the Circuit de Barcelona-Catalunya, was said to have been influenced by a strong, gusty wind.
He was driving at a speed of 215km/h (133.6mph) when he lost control of his car, hit a wall, suffered two blows to his head and was flown to hospital, where he was kept for three nights.
McLaren boss Ron Dennis said four days after the incident that Alonso was not concussed and Coulthard added: "There is conflicting information coming out, saying there are zero signs of any injury but then three days of hospital for concussion.
"It does not add up. He does not need three days of privacy, he can go to his own private residence and have that."
Coulthard was speaking on the F1 preview programme, which will be broadcast on BBC Red Button on Tuesday 10 March at 22:00 GMT.