A search team has recovered the cockpit voice recorder from the EgyptAir plane that crashed into the Mediterranean Sea last month, in a major step towards establishing the cause of the tragedy.

The device was found broken into pieces but the salvage experts managed to retrieve the recorder's crucial memory unit, Egypt's civil aviation authority said on Thursday. It was located by a diving robot operated by Mauritius-based Deep Ocean Search.

Officials are preparing to transfer the recorder from a search vessel to the city of Alexandria on Egypt's Mediterranean coast for analysis, a statement said.

READ MORE: Crashed EgyptAir MS804 wreckage finally found

The cockpit voice recorder keeps track of up to two hours of conversations and other sounds in the pilots' cabin.

Upon arriving in Egypt, the prosecutors would receive the device and hand it over to the investigators to access and analyse the recordings, the authority said in the statement.

An investigator from France's BEA air safety agency is to travel to Cairo on Friday to offer "technical expertise on taking readings from the recorder", the agency said.

 

Unlocking the mystery

The EgyptAir Airbus A320, en route to Cairo from Paris, had been cruising normally in clear skies on an overnight flight on May 19 when it crashed.

The radar showed that the aircraft turned 90 degrees left, then a full 360 degrees to the right, plummeting from 38,000ft to 15,000ft before disappearing at about 10,000ft.

Leaked flight data indicated that a sensor detected smoke in a lavatory and a fault in two of the plane's cockpit windows in the final moments of the flight.

Airbus said the flight recorders held the key to unlocking the mystery of why the plane went down with 66 people on board en route from Paris to Cairo nearly a month ago.

Some wreckage had already been pulled out of the Mediterranean by search teams, along with belongings of passengers.

READ MORE - Timeline: Major air disasters

The passengers on the plane were 30 Egyptians, 15 French citizens, two Iraqis, two Canadians, and citizens from Algeria, Belgium, Britain, Chad, Portugal, Saudi Arabia and Sudan. They included a boy and two babies.

Seven crew and three security personnel were also on board.

EgyptAir crash wreckage spotted on seabed

Source: Agencies