Underwater signals from of the black boxes of EgyptAir flight MS804 have been detected, in a significant breakthrough in investigations into its crash.

Egypt's Ministry of Civil Aviation said in a statement the signals were picked up by a French Navy ship searching for the wreckage of the Airbus A320 in the Mediterranean Sea. However, there has been no update from the French authorities regarding the finding.

"Search equipment aboard French naval vessel Laplace, has detected signals from the seabed of the search area, which likely belong to one of the data boxes," Egyptian statement said.

There were 66 people on board when the plane crashed on 19 May while flying from Paris to Cairo. According to earlier reports, the aircraft vanished from the Greek and Egyptian radar screens, apparently without having sent a distress call.

The search teams have been working continuously to recover the flight recorders which will give important information about the accident.

Apart from the French vessel, another ship will join the team later this week to search and retrieve the devices.