Special prosecutors on Sunday requested an arrest warrant against a former senior presidential secretary involved in an influence-peddling scandal surrounding President Park Geun-hye and her confidante.

Woo Byung-woo, former senior presidential secretary for civil affairs, is accused of aiding and abetting Choi Soon-sil, Park's friend of 40 years, in meddling in state affairs and disrupting a special presidential inspector's investigation into the scandal.

The special prosecutors, who are investigating the scandal that has led to the president's impeachment, summoned Woo on Saturday to question him over the allegations.

The warrant was sought on charges including abuse of authority and dereliction of duty.

Woo has repeatedly denied being acquainted with Choi.

The former prosecutor is seen as the last key figure in the scandal to be targeted by the special prosecutors. On Friday, the team led by Independent Counsel Park Young-soo arrested Lee Jae-yong, the de facto leader of Samsung Group, over allegations he bribed Choi and the president in exchange for business favors related to his management succession plan.

The prosecutors have requested an extension of their mandate, which is set to expire on Feb. 28. It can be extended once by 30 days with consent from Acting President and Prime Minister Hwang Kyo-ahn.

Meanwhile, the Constitutional Court has been reviewing the president's impeachment to determine whether to oust or reinstate her. (Yonhap)