An investigation into former President Yoon Suk Yeol's alleged interference with the probe of the 2023 death of a Marine has been extended by 30 days.

At a press briefing on Friday, assistant counselor Choung Min-young said the special counsel team had elected to extend the investigation, an action permitted under the revised special probe law, after becoming aware of additional potential charges, including destruction of evidence and perjury.

Choung said the team briefed the National Assembly and President Lee Jae Myung in writing about the extension, which would allow continuation of the probe until October 29.

Referring to a provision in the revised law that stipulates reduction in punishment for those who confess to an offense or give a key testimony that could determine the offense of another person, Choung said the team intends to actively apply the provision.

An official from the team said that many are still not cooperating with the investigation and that the provision may convince them to change their minds.