A voice recorder from the cockpit of the crashed EgyptAir Flight 804 has been recovered, the BBC reported Thursday morning. 

Egyptian investigators said it was found in the Mediterranean Sea during a search north of the Egyptian coast carried out by a vessel with an underwater robot. The Paris-to-Cairo flight apparently crashed into the Mediterranean on May 19, killing all 66 people on board. 

The recovery of the voice recorder follows the discovery of some of the plane's wreckage, which was found Wednesday. It remains unclear what brought the aircraft down, but terrorism has not been ruled out. 

The so-called black box recorder is a key component to discovering what happened to the crashed plane. It should allow authorities to hear conversation in the cockpit between the pilot and co-pilot, as well as alarms in the background.

"The vessel's equipment was able to salvage the part [of the recorder] that contains the memory unit, which is considered the most important part of the recording device," investigators said. 

Another black box, reportedly yet to be found, tracks the flight data. Debris from the wreckage, including luggage and body parts, have been found some 180 miles from Alexandria, Egypt. 

A recent report from investigators found that the plane, an Airbus SE A320, was heading to Cairo from Paris when it suddenly veered left off-course at about 37,000 feet. It then made a sharp right turn and completed a full circle. Radar data suggested there was no sudden midair explosion. Electronic messages sent by the plane indicated some smoke alarms did go off.