South Korean special prosecutors have raided the home of a former top presidential aide.

A team seized a number of documents during an early morning swoop on the central Seoul residence of Kim Ki-Choon, who served as Park Geun-hye's chief of staff between 2013 and 2015.

The raid is part of a probe into a huge corruption scandal, focused on Park's long-time friend Choi Soon-Sil. She is on trial for extortion and abuse of power.

Kim Ki-Choon has a long association with Park's family. Those close ties have led to allegations that he must have known of Choi's influence over the president.