Samsung is about to put an end to the on-going speculation on what caused some Galaxy Note 7 smartphones to overheat and in some cases, burst into flame.

The smartphone maker is expected to release the results of its investigation on January 23, a person familiar with the matter told Reuters. In it, Samsung will reveal that the battery was the main reason for the fires—not a design flaw or firmware issue.

The South Korean giant found itself on the hot seat when it recalled an estimated 2.5 million Note 7 phones in September after customers started reporting spectacular failures of their new purchase with flames and smoke coming out of the battery compartment. Samsung initially connected the explosions to batteries produced by Samsung SDI, an affiliate company, which supplied 70% of Note 7 batteries.

After the first recall, Samsung asked Amperex Technology (ATL) to step in and supply batteries for replacement phones. But the new Note 7s with ATL batteries also started blowing up, forcing the company to scrap its Note 7 smartphone and completely halt production.

To regain consumer trust, analysts believe it is critical for Samsung to have "a convincing and detailed explanation."

"They've got to make sure they come clean and they've got to reassure buyers as to why this won't happen again," IDC analyst Bryan Ma told Reuters.

In October, Samsung announced it will investigate all aspects of the Note 7, and hired third-party firms to help with the probe. The source told Reuters "Samsung was able to replicate the fires during its investigation and that the cause for the fires could not be explained by hardware design or software-related matters."

According to the information posted by the United States Consumer Product Safety Commission, Samsung has received 92 reports of the batteries overheating in the United States, including 26 reports of burns and 55 reports of property damage, including fires in cars and a garage.