McLaren: 'Nothing to hide' over Fernando Alonso's F1 testing crash

Since Alonso crashed during the second pre-season test at Barcelona in February, leading to him sitting out the Australian Grand Prix, there has been widespread speculation about both the cause of the accident and Alonso's condition.

But Boullier stressed that the reason relatively little information has been released is that no car problems have been found and Alonso's medical privacy should be respected as the Spaniard works towards his return after suffering a concussion.

"We first cared about Fernando being cared for by the doctors and, as far as I know, that is a personal thing so nobody has access to the medical files except the doctors," said Boullier.

"The second thing [is that], technically, on the car, we have conducted all the investigations very transparently and openly with the FIA.

"Everything we have conducted so far, we couldn't find anything wrong or which has implied the accident.

"We are still looking for further investigations, but we have given our report to the FIA and we are working with the FIA.

"Nothing else can be said on this. We have nothing to hide."

Boullier added that Alonso's subsequent medical checks have gone well, but that medical specialists will have the final say on whether Alonso makes his planned comeback at the Malaysian GP in two weeks.

"Any medical information stays within the medical field," said Boullier.

"We have a doctor at McLaren who has access to the information, but this is not public.

"As far as we are concerned, the doctors are happy with all the checks, all the scans, everything that has been conducted to Fernando.

"The only thing is, the final decision for Fernando to be back is for the doctors of the FIA."