A postal service vehicle is parked near the presidential office in Yongsan District, Seoul, Monday. Yonhap

The Constitutional Court will proceed with President Yoon Suk Yeol's impeachment trial, despite his continued refusal to receive court notifications. The court considers the documents to have been effectively delivered, it said on Monday.

The court's decision comes as Yoon has been ignoring court notifications for over a week, which critics view as a deliberate tactic to delay proceedings on his impeachment motion, passed by the National Assembly in response to his short-lived martial law order.

"The effectiveness of the document delivery, as per Supreme Court precedents, takes effect the moment the documents reach the intended delivery address. The delivery is considered valid even if the recipient does not physically accept it," court spokesperson Lee Jin said during a press briefing.

Therefore, documents on Yoon's impeachment trial, delivered via postal service to his residence last Friday, are considered valid, the spokesperson added.

Lee reaffirmed the court's plan to hold a pretrial hearing this Friday. The session, which takes place before public argument hearings, aims to clarify key issues of the trial, review evidence, and determine the selection of witnesses in advance. Yoon is not required to attend Friday's hearing.

President Yoon Suk Yeol delivers a public address from his residence in Seoul, Dec. 14, after the National Assembly passed his impeachment motion. Courtesy of presidential office

Since the initial notification on Dec. 16, attempts to deliver the documents by mail and in person have failed. Mail sent to the president's residence was refused by his security team, while deliveries to the presidential office were returned, as officials there claimed that no recipient was available.

Yoon has also ignored court orders requesting the submission of records related to the Dec. 3 martial law decree, as well as written records of two Cabinet meetings held before and after the declaration of the emergency military rule.

"Refusing the court documents is likely just the start of Yoon's apparent strategy to deliberately delay the trial, who, in the meantime, is attempting to woo his remaining supporters. The trial could face additional delays due to Yoon's uncooperative stance," Lim Ji-bong, a constitutional law professor at Sogang University, told The Korea Times.

Lim suggested the cornered president might use further stalling tactics, such as claiming his legal team is unprepared — which he has already been arguing — or requesting an extensive list of witnesses to complicate the proceedings.

The professor added that Yoon could attempt to invoke Article 51 of the Constitutional Court Act, which allows the suspension of impeachment trial proceedings if a criminal trial is underway for the same reasons.

In this case, Yoon — currently under criminal investigation for treason over his failed martial law bid — might argue that the impeachment trial should be paused, if he is indicted.

"But I believe the Constitutional Court will be capable of swiftly proceeding with the trial despite such attempts," Lim said.

Police officers guard the main gate at the Constitutional Court in central Seoul, Monday. Yonhap

Yoon's duties were suspended following his impeachment by the Assembly on Dec. 14. The Constitutional Court is expected to rule on his impeachment within six months. If upheld, Yoon would become the second conservative president to be removed from office in a row, following former President Park Geun-hye's impeachment in 2017.

Despite the lengthy legal battle ahead, Yoon has yet to finalize his legal team, amid speculation that high-profile former prosecutors are expected to represent the prosecutor-turned-president.

Seok Dong-hyeon, a former prosecutor and Yoon's longtime acquaintance, is serving as the temporary legal adviser and representative for the press. Other rumored members include Kim Hong-il, a former chairman of the Korea Communications Commission and Yun Gap-geun, a former chief prosecutor at the Daegu High Prosecutors' Office.

Seok denied speculation that Yoon is deliberately avoiding court notifications.

"The president will put more priority on the impeachment trial than the criminal investigation…. It is not (his) intention to delay or avoid the trials, but his current stance is based on the notion that there needs to be thorough preparation for court proceedings," Seok told reporters shortly after the Constitutional Court's briefing.

He declined to elaborate on the court's decision deeming the legal documents as effectively delivered to Yoon, saying that those issues will be addressed by his legal defense team once it is officially formed.

People stage a rally at Namtaeryeong Pass in Seocho District, southern Seoul, Sunday, demanding the arrest of President Yoon Suk Yeol. Korea Times photo by Choi Won-suk

Meanwhile, law enforcement authorities are accelerating their investigation into Yoon's alleged treason.

Investigators have obtained Yoon's phone records which may contain orders he allegedly gave to key military officials who were dispatched to the Assembly during the martial law incident.

Additionally, they have secured a document passed on to Finance Minister Choi Sang-mok during the Cabinet meeting held before the martial law order, in which Yoon reportedly directed him to "cut off funds for the National Assembly's operation and allocate legislative budgets under a martial law scenario."

A joint team comprising the National Police Agency, the Corruption Investigation Office for High-ranking Officials (CIO) and the Ministry of National Defense has summoned Yoon to appear for questioning at the CIO office by Wednesday at 10 a.m.

However, the chance of him appearing appears to be slim.

The CIO said Monday that its summons — sent to Yoon's residence and the presidential office on Friday — were not accepted by the recipient, marking the second time Yoon has ignored the summons request.