Egypt has enlisted the help of three European companies to search for the black boxes of downed EgyptAir Flight MS804, which crashed into the Mediterranean Sea on 19 May. EgyptAir chairman Safwat Musallam did not name the French and Italian companies involved but told reporters they were able to conduct searches at a depth of 3,000 metres.

According to Reuters, two French diplomatic sources claimed Egyptian authorities and France's BEA air accident investigation agency were finalising a contract with two French companies: Deep Ocean Search and Alseamar. "The objective is to go extremely quickly so they can find the boxes that are probably in very deep waters," one source said, according to the report released on Wednesday (25 April).

The same source also told Reuters that the costs of the contract would be split between France and Egypt. The name of the Italian company was not identified.

While debris and human remains from the doomed Paris-to-Cairo flight have been found, the plane's main body and cockpit data and voice recorders—better known as black boxes—have not been found. The black boxes are believed to be submerged in deep water of up to 3,000 metres and on the edge of the range for hearing and locating their signals, The New York Times reported.

Acoustic hydrophones will need to be towed in the water at depths of up to 2,000 metres in order to pick up the location signals, maritime search experts say. According to The Guardian, aviation sources said that, until recentl, the US Navy or its private contractor, Phoenix International, were considered among the only sources for the equipment need to conduct such deep water searches. But on Tuesday (24 May), the US Navy said it had not been asked for help.

Egypt previously deployed a submarine to search for the missing black boxes, which have enough battery life to emit a location signal for 30 days.

Despite the time constraint, EgyptAir's deputy chairman, Ahmed Adel, said the search would continue beyond the 30 days if necessary using other means to locate the black boxes. "There are many examples in similar air accidents when 30 days passed without finding the box yet" these planes' black boxes were found, Adel said.

Musallam maintained that the jetliner had reported no signs of technical problems before taking off from Paris. The Airbus A320 was reportedly given a regular check by an Egyptian engineer and two Egyptian technicians in Paris. "The engineer and the pilot both signed the aircraft technical log, which stated that the check found all the plane's machines were safe," he said.

There have been conflicting reports regarding the flight's final minutes, before it plummeted into the Mediterranean with 66 passengers on board. Egyptian officials insist the plane did not swerve prior to dropping out of the radar after entering Egyptian airspace, contradicting an earlier account by Greek Defence Minister Panos Kammenos.

Egypt's Forensic Medicine Authority chief, Hisham Abdul Hamid, also dismissed reports that an initial examination of human remains suggested there had been an explosion.