Samsung Electronics Co Ltd's investigation into what caused some Galaxy Note 7s to catch fire has concluded that the battery was the main reason, a person familiar with the matter told Reuters on Monday.

The world's biggest smartphone maker will likely announce the results of the investigation on January 23, a day before it announces detailed fourth-quarter earnings results, said the person who was not authorised to speak publicly on the matter and declined to be identified. The firm will also announce new measures it is taking to avoid a repeat of the product safety ...