The way in which the Australian-led search for the missing Malaysia Airlines Flight 370 could be subject to imminent review if no fresh leads are forthcoming.

Bernama, the official Malaysian news agency, reporting discussions between the Australian prime minister Tony Abbott and his Malaysian counterpart Datuk Seri Najib Tun Razak, said that the approach to the search effort may be examined and adapted.

Bernama quotes acting transport minister Datuk Seri Hishammuddin Tun Hussein as saying: “Abbott said that if within a stipulated time, not in terms of days but in terms of what information we received, (we) did not achieve the target, an announcement will be made whereby, we may have to relook and reconsider the approach used.”

“…this does not mean we will stop the search operation but it is about how the search is carried out, and possibly where,” he told a press conference, adding that any action concerning the search mission would not be carried out without joint discussion.

Flight 370 with 239 people departed on March 8 from Kuala Lumpur International Airport at 12.41am and disappeared from radar, an hour later over the South China Sea. The aircraft was scheduled to arrive in Beijing at 6.30am on the same day.

A search and rescue operation involving 26 countries was launched to find the aircraft, beginning in the South China Sea and then expanded to the Malacca Strait and Andaman Sea and now in the southern Indian Ocean.

Chief coordinator of the Joint Agency Coordination Centre, Air Chief Marshal Angus Houston, answering question at a press conference for Chinese media on April 14 said the search effort had reached a stage in the visual search where further efforts were unlikely to yield results.

“We’ve done the visual search; we’ve found nothing. We’ve now done the Towed Pinger Locator search; we have found some transmissions. We now need to go down and visually search in the area of those transmissions. Now, I’m very hopeful that we find something. But if we don’t, and that is a possibility, there’s no doubt about that—until we find the wreckage, we can’t be certain about anything. I think if we can’t find anything in that location, we then have to go back and talk to the partners and work out what happens next,” he said, adding that consultation will likely take place later this week and include the People’s Republic of China.

He said that based on the search effort for Air France Flight AF447 which crashed in the Atlantic Ocean in 2009 that would probably mean a similarly ‘long, very painstaking’ sonar search of the floor of the ocean along the arc of the seventh ping. “So that would take an extraordinary amount of time, would be very expensive but eventually, I would hope, it would yield information about what might have happened,” said Houston.

Houston today said that a preliminary analysis of an oil slick sample collected by the Australian Defence Vessel Ocean Shield indicated that it was not aircraft engine oil or hydraulic fluid.

Additionally, Phoenix International, with the assistance of Bluefin, have assessed that there is a small but acceptable level of risk in operating the vehicle in depths in excess of 4,500 metres. This expansion of the operating parameters will allow the Bluefin-21 to search the sea floor within the predicted limits of the current search area.

Houston said the underwater search has been significantly narrowed through detailed acoustic analysis conducted on the four signal detections made by the Towed Pinger Locator on ADV Ocean Shield.

“This analysis has allowed the definition of a reduced and more focused underwater search area,” said Houston. “This represents the best lead we have in relation to missing Flight 370 and where the current underwater search efforts are being pursued to their completion so we can either confirm or discount the area as the final resting place.”

Read: Bluefin-21 at operational limits, underlining MH370 challenges