Japanese officials investigating alleged defects in the battery of a Boeing 787 Dreamliner that made an emergency landing earlier this month say that the manufacturing process did not cause problems inside the battery.

GS Yuasa, the Japanese battery maker, has been at the center of the controversy surrounding alleged problems with the battery of an All Nippon Airways 787 which made an emergency landing in Japan on January 16. 

"There were several reports on quality control issues, but there was nothing that would have caused an immediate problem inside the battery," said Shigeru Takano, director of the air transport safety unit of the Civil Aviation Bureau, on Monday. 

US and Japanese authorities are investigating fire and smoke incidents with lithium-ion batteries on two seperate Dreamliners in recent weeks, prompting aviation officials to ground the aircraft indefinitely.

On Sunday, US safety regulators said that "no obvious anomalies were found" in their initial investigation of an undamaged battery aboard a Dreamliner which caught fire while parked at Boston's Logan international airport.

Boeing's chief rival, Airbus, had warned the airline industry of risks related to lithium batteries in March 2012, citing the risk of flames, explosion, smoke or leakage in the event of uncontrolled battery overheating.

Airbus, however, plans on using lithium-ion batteries on its upcoming A350 jetliner.

Stefan Schaffrath, a spokesperson for Airbus, said "Airbus will carefully study recommendations that come out of the 787 investigation and evaluate whether they apply to the A350."

The 787 is the first passenger jet to use lithium-ion batteries for back-up and auxiliary power.

Source: Agencies