GWACHEON, South Korea - South Korea's suspended President Yoon Suk-yeol did not respond on Wednesday to a second summons by anti-corruption authorities who, along with prosecutors, are investigating his short-lived martial law decree issued early this month.

Yoon had not appeared for questioning as of 10 am (0100 GMT) on Christmas Day as requested by the Corruption Investigation Office for High-ranking Officials, after ignoring their first summons last week.

An agency official said it would continue waiting for Yoon on Wednesday, adding it would need to review the case further before seeking an arrest warrant, Yonhap news agency reported.

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Yoon also did not respond on Dec 15 to a separate summons by prosecutors who are investigating the martial law declaration, Yonhap said.

Yoon's repeated defiance of the summons and failures to appear for questioning have sparked criticism and calls from the opposition for his arrest, citing concerns over potential destruction of evidence.

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In a televised address on Dec 7, four days after the martial law declaration, Yoon said he would not evade legal and political responsibility for his actions.

Yoon was impeached by parliament on Dec 14 over his brief imposition of martial law and must now face a Constitutional Court trial on whether to remove him from office or restore his presidential powers.

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Prosecutors, the police and the corruption investigation office have all launched probes into Yoon and other officials, seeking to pursue charges of insurrection, abuse of power or other crimes.

Insurrection is one of the few charges for which a South Korean president does not have immunity.

A lawyer advising Yoon has said he is willing to present his views in person during legal proceedings related to the martial law declaration.