MH370 search: New signals "most promising lead so far," says JACC chief

Read: MH370 search: Two new signals consistent with black box

"We have not found the aircraft yet, we need further confirmation," he said of the Boeing 777 which vanished on March 8 with 239 people on board.

"It could take some days before information is available to establish whether these detections can be confirmed as being form MH370," he added.

"In very deep oceanic water nothing happens fast."

In total up to nine military planes, three civil planes and 14 ships were taking part in Monday's search operation.

The search area was expected to be approximately 234,000 square kilometres on Monday. Good weather is predicted throughout the day in a region of the Indian Ocean around 2,000 kilometres (1,250 miles) northwest of Perth.