RIO DE JANEIRO — Brazil's air force released a recording Friday it said proves it handed over control of Air France Flight 447 to Senegalese authorities before it crashed — but African officials denied that.

The audio clip was posted on the air force's Web site after a French official investigating the June 1 crash said air traffic controllers in Dakar, Senegal, were never officially given control of the flight by Brazilian authorities.

Lead French investigator Alain Bouillard made the accusation Thursday during the first public report on the crash in the Atlantic Ocean that killed 228 people.

Bouillard said the issue of who was in control of the flight is part of the investigation, but he did not suggest it contributed to the crash. The Brazilian air force said Senegalese officials did not ask about Flight 447's whereabouts until two hours after the plane was expected to be in the African nation's air space.

That delayed launching a search for the missing jet — but Brazilian officials said an air force plane was still in the air at sunrise and began a visual search of the ocean's surface.

The Brazilian air force said in a statement the audio message shows it informed Senegal the Air France flight would enter its airspace at 0220 GMT on June 1. It added that under an agreement between the two nations, controllers need only inform their Senegalese counterparts of a flight's expected arrival to hand over control, and it is up to Senegal to initiate any further contact if a flight does not arrive.

A Senegalese air controller, the statement continued, did not ask about the whereabouts of Flight 447 until 0420 GMT.

However, the Air Navigation Security Agency for Africa and Madagascar, known as ASECNA, said the procedures do not stipulate that if Brazil doesn't hear from Senegalese controllers, they can assume the plane arrived safely.

"There is no measure of this nature in the accord between the Atlantico and Dakar control centers," ASECNA said in a statement.

The agency also said the plane had yet to pass two navigation points in Brazilian airspace when Brazil controllers indicated at what hour the plane was expected to enter Senegalese airspace, and it was Brazil's responsibility to call controllers in Dakar to confirm the plane's arrival.

"This formality was not performed. In addition, the plane never entered in contact with the Dakar center to signal its presence," the statement read.

The Brazilian air force did not immediately respond to the ASECNA statement.