Former President Yoon Suk Yeol will attend a court hearing on Friday to determine the legality of his pretrial detention as part of a special counsel team’s investigation into the December 3 martial law incident.

According to Yoon’s legal team on Thursday, the former president, who has failed to attend the special team’s questioning or his ongoing insurrection trial since he was taken into custody last week, is expected to explain in court how his health has worsened.

Earlier in the week, Yoon submitted the review request to the Seoul Central District Court, with his legal team saying it intends to argue that the former president’s detention is unlawful and unfair both substantively and procedurally.

The court must decide whether to keep Yoon in detention or to release him within 24 hours of the hearing.