Malaysia Airlines MH370 mystery unsolved 100 days on

It is more than 100 days since Malaysia Airlines flight MH370 disappeared en route from Kuala Lumpur to Beijing, but international search teams have yet to find any trace of the missing plane.

The British satellite company Inmarsat, which provided key satellite data to try and locate the aircraft, has suggested investigations have yet to take place in what it calls the "hotspot" area.

It told the BBC that, according to its calculations, the wreckage of flight MH370 lies south west of the area that has been the main focus of the search so far.

Pallab Ghosh reports.

Watch the full Horizon programme on BBC2 at 21:00BST on Tuesday, and on iPlayer afterwards.