South Korea's Justice Ministry on Friday lifted the ban on leaving the country placed on former Defense Minister Lee Jong-sup, who has been named ambassador to Australia, amidst ongoing controversy surrounding the appointment.

The Justice Ministry announced that its travel ban review committee has determined that Lee's formal complaint against his travel restriction was justified.

The ministry elaborated that the ban on him leaving the country had been repeatedly extended without any ongoing investigation, and took into account Lee's recent attendance at the investigation and his willingness to cooperate actively with the process.

In response, the Corruption Investigation Office for High-ranking Officials said on Friday, "We will continue to proceed with the investigation process calmly as before and in accordance with the law and principles to ascertain the facts."

The ambassador appointment has sparked controversy due to Lee having been named a suspect in a military investigation into the death of a young Marine last year, which led to questioning and the travel ban, as well as to Lee resigning as minister under pressure of impeachment.

Lee has been banned from leaving the country since the beginning of this year over an alleged influence-peddling case related to the death of Marine Cpl. Chae Su-geun, according to the COI.

Chae was swept away by an overflowing stream during a search and rescue mission for victims of torrential rains in Yecheon County, North Gyeongseong Province, last July 19. Chae's death sparked criticism that his superiors had forced him to push ahead with a risky operation without proper safety measures in place.

A Marine Corps investigation found eight people responsible for negligent homicide and other charges. Lee is accused of downplaying Chae's death and interfering in the investigation into the incident to vindicate top-ranking Marine officers.

Opposition parties and civic groups voiced criticism over the appointment.

“The dead is silent, the bereaved family is bitter, and the military officer who tried to properly investigate the disaster has been ruined. But the person suspected of external pressure gets a good government job and goes abroad to show off," Lee Jun-seok, leader of the New Reform Party, said at a meeting on Friday.

"What former Minister Lee deserves is not a diplomatic passport, but a thorough investigation."

The Center for Military Human Rights Korea also asserted, "Lee must continue to be investigated here," urging his detention to enable further questioning.

Rep. Hong Ihk-pyo, the main opposition Democratic Party of Korea floor leader, on Thursday questioned President Yoon Suk Yeol's decision to appoint someone already banned from leaving the country to an ambassadorial post.

Lee was questioned by the CIO over the case on Thursday. Lee was reportedly asked about whether he was involved in the Defense Ministry's alleged interference in the military probe into Chae’s death.

Amid the mounting criticism, Lee reportedly postponed his departure from Incheon International Airport for Sydney, which he had planned for Friday afternoon.