SEOUL - South Korea's court denied the second request for extension of the arrested President Yoon Suk-yeol's detention, multiple media outlets said Saturday.

The prosecution's special investigative headquarters requested Yoon's extended arrest from the Seoul Central District Court early Saturday, just hours after the court rejected the first request on Friday night.

The court ruled that the prosecution had no right to conduct a supplementary investigation into Yoon's case, referred by the anti-corruption agency which had already investigated the case, as the prosecution is only required to decide whether to indict Yoon.

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

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, making Yoon the country's first incumbent president to be formally arrested.

Yoon was apprehended in the 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as a suspected ringleader on an insurrection charge, declared martial law on the night of Dec 3 last year, but it was revoked by the National Assembly hours later.