A British satellite communications company today said it had recorded electronic ping signals from the missing Malaysian aircraft which could be analysed to help estimate its location.
As the hunt for Flight MH370 remained inconclusive, the information from Inmarsat could prove to be a valuable break in the frustrating search for the plane with 239 people aboard that mysteriously vanished from radar screens last week.
Inmarsat described the communication signals from the plane as "routine" and "automated", without disclosing any details regarding the timing of the signals in relation to the aircraft's disappearance on March 8.
Inmarsat said in a statement that it handed the information to communications specialist SITA which, it adds, has shared the data with the airline.
It has not stated which satellites were involved. Inmarsat operates about 10 geostationary satellites through which it handles satcom datalink transmissions including those from the aeronautical sector.
Until now, that search has turned up false leads: oil slicks, chunks of foam, life vests and other debris unconnected to the vanished plane.
But a series of electronic pings sent by the aircraft could help the search, which is shifting focus from the confines of the Gulf of Thailand and nearby waters to include the Indian Ocean on the western side of Malaysia.
It emerged that electronic 'pings' from the aircraft continued for over five hours after all other contact was lost.
Evidence from Malaysia's air force corroborated the theory that the plane turned from its north-north-east course to head west.
The final satellite contact was at 8.11am GMT, five-and-a-half hours after the jet's last known position.
During that time, the aircraft could have flown 3,000 miles at its normal cruising speed.
The maximum range of the Boeing 777ER aircraft type is over 8,000 miles, but the flight was carrying only enough fuel for the planned 2,700-mile flight to Beijing plus a contingency for holding and diversions.
Malaysia turned the search for the plane into a criminal investigation after Prime Minister Najib Razak declared that the plane had been deliberately diverted from its planned route to an unknown destination.
Najib said that Malaysia would seek help of other governments across a large region of Asia to find the plane.