The search leader hunting for missing Malaysian flight MH370 said on Tuesday that no submersible onboard the Australian vessel "Ocean Shield" would be deployed unless the ship detects more credible signal.

Angus Houston, head of the Joint Agency Coordination Center ( JACC), confirmed to reporters that the "Ocean Shield" had failed to receive more transmissions since it detected electronic pulse signals twice two days ago.

He said more detection is very important since it can "enable a much more narrowly focus on visual search for wreckage."

"The towed-pinger locator work continues, there have been no further contacts with any transmission and we need to continue for several days right up to the point at which there's absolutely no doubt that the batteries will have expired," Houston said.

He said there would be no deployment for the submersible unless "Ocean Shield" gets another transmission which "we would have a better idea what's down there and we will go down there to have a look".

"If we go down now and scour the ocean floor, it will be painstaking work," he added.

According to Australia's Defence Minister David Johnston, his country is "throwing everything on the difficult and complex task" and he predicts "several days of intense action" ahead of the search team since the lead was positive.

The towed-pinger locator deployed from the "Ocean Shield" detected signals consistent with those emitted from aircraft black boxes on Saturday and Sunday.

Houston described the new leads as "very encouraging and promising", saying it might be "the best information" the international search team has now.

Up to 11 military planes, three civil planes and 14 ships are scheduled to assist in Tuesday's search for MH370.

The search area is expected to be approximately 77,580 square kilometers, and good weather is also expected for searching throughout the day.

According to the JACC, the underwater search continues on Tuesday, with "Ocean Shield" at the northern end of the defined search area, and Chinese ship Haixun 01 and British HMS Echo at the southern end.