PARIS - Lengthy legal procedures in Brazil are slowing down a French inquiry into last month's Air France crash and Brazilian autopsy reports are still to be released, a French magistrate said on Wednesday.

French police sent by examining judges have visited the Brazilian institute charged with medical and legal examinations, but still lacked basic information related to Air France flight AF-447, which crashed into the Atlantic with 228 people aboard.

Authorities in Brazil have refused to hand their French counterparts the results of autopsies on 51 bodies, for example, as they had only begun so-called administrative proceedings and had not yet opened a formal judicial inquiry, he said.

So from their point of view, they can't proceed with formal judicial cooperation, the judge said.

The Airbus A330 aircraft was en route for Paris from Rio de Janeiro when crashed into the Atlantic on June 1, apparently hitting the water intact and at high speed, according to French investigators.

The cause of the accident is still unknown and French crash investigators have said that access to autopsy reports might give them more clues as to how the aircraft was destroyed.

Last week, France's BEA air accident board reiterated unease that the country had not yet been granted access to autopsy reports on bodies taken to Brazil and said these would provide helpful clues in the investigation.

(Reporting by Thierry Leveque; Editing by Louise Ireland and James Mackenzie)