SEOUL -- South Korea's prosecution sought the extension of detention of the arrested President Yoon Suk-yeol until Feb 6 to carry out further investigation, multiple media outlets said Friday.

The prosecution's special investigative headquarters made the request to the Seoul Central District Court on Thursday, which was predicted to decide on the extension as early as Friday.

A warrant to keep Yoon in custody for up to 20 days, including the arrest period, was issued by another Seoul court on Jan 19.

The prosecution was widely expected to indict Yoon under detention for insurrection and other charges.

Yoon was apprehended in presidential office on Jan 15, becoming the country's first sitting president to be arrested.

The motion to impeach Yoon was passed through the National Assembly on Dec 14 last year and was delivered to the constitutional court to deliberate it for up to 180 days, during which Yoon's presidential power is suspended.

Yoon, who was named by investigative agencies as a suspected ringleader on insurrection charge, declared a martial law on the night of Dec 3, but it was revoked by the National Assembly hours later.