Australian search co-ordinators say a Chinese ship’s detection of a pulse signal in the southern Indian Ocean is an “important and encouraging lead” according to a BBC report.
China advised that the Haixun 01 had redetected the signal for 90 seconds within 24 hours of first picking up the pulse, retired Air Chief Marshal Angus Houston said.
He warned that the data were still unverified.
Australian aircraft have been sent to the area to investigate further.
British naval ship HMS Echo is en route to the area, Air Chief Marshal Houston says, and will be followed by Australian naval vessel Ocean Shield which is investigating a separate acoustic detection elsewhere.
Both vessels have technology able to detect underwater signals emitted by data recorders.
In addition, a dozen military aircraft and 13 ships are already searching three areas about 2,000 km (1,240 miles) north-west of the Australian city of Perth.
They will cover some 216,000 sq km on Sunday.
Flight MH370 disappeared en route from Kuala Lumpur to Beijing four weeks ago with 239 people on board.
The plane is believed to have crashed in the southern Indian Ocean, although no confirmed debris has been found.