Former South Korean President Yoon Suk Yeol has filed a legal petition challenging the legitimacy of his recent arrest over charges related to an alleged attempt to impose martial law, his lawyers said on Wednesday.

The petition was submitted to the Seoul Central District Court, claiming that Yoon’s arrest was both “illegal” and “unjust” on procedural and substantive grounds. Under South Korean law, the court must review the evidence and question the suspect within 48 hours of the petition being filed to decide whether the arrest remains valid.

Yoon has been in custody at the Seoul Detention Center since last Thursday after a court issued an arrest warrant on five charges linked to his failed martial law attempt. If the court rules in his favor, Yoon could be released from detention.

This is not the first time Yoon has contested his detention. In January, following his initial arrest, the court initially upheld the legality of his detention. However, a subsequent petition led to his release in March.

Meanwhile, the special counsel team investigating the case, led by Cho Eun-suk, attempted once again on Tuesday to bring Yoon in for questioning. Authorities at the Seoul Detention Center were asked to present him for interrogation at 2 p.m., but the former president has repeatedly refused to comply with summonses since his latest arrest.

The case has stirred political tensions and public debate in South Korea, as the charges involve attempts to subvert constitutional order.