An Australian ship scouring the Indian Ocean for missing flight MH370 has detected two further pings consistent with the plane's two black boxes, in a "great lead", bolstering hopes for wreckage discovery.

The Australian Defence Vessel Ocean Shield, towing a US pinger locator, detected two sets of pings, on Tuesday afternoon and then again about five hours later.

The signal detected on Tuesday afternoon was held for about five minutes and 32 seconds; followed by a second signal on Tuesday night, which was held for seven minutes.

The development came more than two days after Ocean Shield first detected the month-long search's most promising lead: two acoustic events on Saturday.