Egyptian search teams detected an emergency signal from the wreckage of EgyptAir Flight 804 that could help them locate the aircraft’s fuselage on the floor of the Mediterranean Sea, the lead investigator into the disaster said Thursday.

The discovery of the signal is a potentially significant break for the Egypt-led search, which so far has been limited to recoveries of small pieces of debris and human remains.

The Airbus Group SE A320 aircraft, traveling from Paris to Cairo with 66 passengers and crew aboard, crashed on May 19.

The investigator, Capt. Ayman Al Moqadem, told Egypt’s flagship state newspaper Al Ahram that the detection of the signal by satellite narrowed the search zone for the main body of the plane to a radius of about 3 miles.

Egyptian officials had said their search was focused on a much broader area of the Mediterranean.