The examination of a South Korean government body found battery defects in the fiery Galaxy Note 7 smartphones of Samsung Electronics that had been discontinued for overheating and explosion, a government report showed on Monday.

It was highly likely that the manufacturing error in batteries used for Note 7s was the root cause of catching fire, Korea Agency for Technology and Standards (KATS)'s findings showed. The KATS is a government body in charge of technology standards under the Ministry of Trade, Industry and Energy (MOTIE).

No problem with the Note 7 gadget's hardware and software was found in the investigation, the state-run agency said, confirming Samsung's earlier announcement on Jan. 23 of its own independent third-party examination.

Note 7s were launched in August last year, and Samsung was shortly thrown into embarrassment as multiple devices, set on fire without any external cause, were reported.

In September, Samsung issued a global recall of about 2.5 million gadgets, but continued reports of replacement phones catching fire forced the company to discontinue the product in October.

To prevent any battery-linked incident, the ministry plans to force batteries of new smartphones to be re-tested every two years by the KATS, while raising safety standards for mobile phone batteries.