S. Korea's Park hires lawyer ahead of questioning

South Korean President Park Geun-Hye has hired a lawyer ahead of questioning by prosecutors over a snowballing political scandal that has engulfed her administration, her spokesman said Tuesday.

Park, who would be the first sitting president to be interrogated in a criminal case, has seen her approval ratings plunge, with hundreds of thousands of protesters taking to Seoul's streets on Saturday demanding she resign.

The scandal centres on Park's shadowy confidant Choi Soon-Sil, who is accused of using her ties with the president to coerce local firms to donate millions of dollars to non-profit foundations that Choi then used for personal gain.

Choi, whose father was an elusive religious figure and a long-time mentor to Park until his death in 1994, was arrested earlier this month for abuse of power and fraud. Two presidential aides have also been arrested.

Choi, 60, is also accused of interfering in state affairs to the extent of nominating officials and editing Park's speeches even though she has no official title or security clearance.

Prosecutors on Sunday announced a plan to formally quiz Park this week over allegations she helped Choi extract money from the firms and allowed presidential aides to leak documents to Choi.

Park's newly retained lawyer, Yoo Young-Ha, will discuss with Seoul prosecutors exactly when, where and how Park would be questioned, Park's spokesman told reporters.

Yoo, 54, is a former prosecutor and is currently a standing committee member on Seoul's human rights commission.

Under South Korea's constitution, the incumbent president may not be charged with a criminal offence except insurrection or treason.

But many have argued the sitting president can be investigated by prosecutors and then charged after leaving office.