British satellite company Inmarsat claims that searchers for Malaysia Airlines Flight MH370, which disappeared 103 days ago with 239 passengers and crew aboard, are yet to look in the area its scientists think is the most likely crash site.
Inmarsat's hourly communications with MH370, which was on a flight from Kuala Lumpur to Beijing, are the only clues to the location of the Boeing 777.
Yesterday, Inmarsat experts told the BBC's Horizon program that when the search resumed in August, with equipment capable of searching as deep as 6000m, its "hotspot" would be a key focus.
Inmarsat's Chris Ashton told the BBC the area searched by the Ocean Shield vessel related to apparent black box pings that were picked up.
"It was by no means an un- realistic location but it was further to the north-east than our area of highest probability," Mr Ashton said.
Inmarsat's experts used satellite data to plot a series of arcs across the Indian Ocean where its systems made contact with the Boeing 777.
According to the BBC Horizon program, by modelling a flight with a constant speed and a constant heading consistent with the plane being flown by autopilot, the team found one flight path that lined up with all its data.
"We can identify a path that matches exactly with all those frequency measurements and with the timing measurements and lands on the final arc at a particular location, which then gives us a sort of a hotspot area on the final arc where we believe the most likely area is," Mr Ashton said.
The Australian Transport Safety Bureau has awarded a contract to deepwater survey company Fugro Survey to conduct a bathymetric survey of the seafloor.
The bathymetric survey will provide a map of the under- water search zone, charting the contours and depths and will be crucial to help plan the deep- water search.
Fugro will use the state-of-the-art vessel MV Fugro Equator, which is equipped with a deepwater multibeam echo sounder system and carries expert survey personnel.
The ATSB has also invited proposals to conduct the underwater search once the mapping is under way.
According to the ATSB, the successful prime contractor will provide the expertise, equipment and vessels necessary to do an intensified underwater search.