KUALA LUMPUR, April 5 — The batteries of the missing Flight MH370’s “black box” emergency locator transmitters are only due for replacement in June, Malaysia Airlines (MAS) said today.

The national carrier’s remarks come after US news network CNN reported earlier today that the so-called “pingers” were scheduled for battery replacements in 2012, but that MAS had not done so, causing the effective battery life on the crucial device to drop from 30 days to possibly 25 or 20 days.

“The batteries were due for replacement only in June 2014,” MAS CEO Ahmad Jauhari Yahya told a press conference here today.

Searchers are racing against time as the black box is expected to stop emitting signals on Monday, 30 days after the Boeing 777-200ER jet carrying 239 disappeared on March 8.

UK paper The Guardian reported yesterday that a sonic trawl of a swathe of the southern Indian Ocean has begun.

Aviation experts, however, have warned that the black box on Flight MH370 may not reveal key information as only the last two hours of cockpit communication will be kept.

The crucial moments of the Beijing-bound flight were when the plane’s communications systems were disabled, just after leaving Kuala Lumpur air traffic control, after which the jet deviated from its flight path in a westerly direction and flew on silently for about seven hours.

When asked if Malaysia believes that the plane had crashed, Acting Transport Minister Datuk Seri Hishammuddin Hussein noted today that Prime Minister Datuk Seri Najib Razak had merely said that the plane ended in the southern Indian Ocean.

“This is the hope of the families, that in whatever situation, maybe they had survived,” Hishammuddin said.

“So we must keep praying and keep hoping against hope. If those are the wishes of the family, we must respect them,” he added.