On Sunday prosecutors formally charged the South Korean president's longtime friend Choi Soon-sil on suspicion of interfering with state affairs and bullying companies into giving tens of millions of dollars to foundations and businesses she controlled. The damning allegations say the 60-year-old daughter of a late cult leader exploited her friendship with the president to amass an illicit fortune, a revelation that may convince opposition parties to push for the president's impeachment.

Chief prosecutor Lee Young-ryeol of the Seoul Central District Prosecutors' Office said during a televised news conference that based on evidence, "the president was involved as a conspirator in a considerable part of the criminal activities by suspects Choi Soon-sil, Ahn Jong-beom and Jung Ho-sung." He referred to two presidential aides who also were formally charged Sunday for allegedly assisting Choi.

 The president enjoys immunity from prosecution under South Korea's constitution, meaning it will be up to lawmakers to allow the criminal probe to go forward, he said. There are exceptions for "cases of insurrection or treason," but it would be up to lawmakers to take action.

The president's office had no immediate comment Sunday. It comes a day after at least 170,000 people rallied in central Seoul for the fourth weekend demanding the president's resignation. Her popularity is at an all-time low with even her own supporters cynically referring to themselves as "the 5 percent."

Companies coerced into funneling millions to Choi's enterprises

Ahn Jong-beom, Park's former senior secretary for policy coordination, was charged with abuse of authority, coercion and attempted coercion over allegations that he pressured companies into making donations to businesses and foundations Choi controlled. Jung Ho-sung, the other former aide who was indicted, was accused of passing on classified presidential documents to Choi, including information on ministerial candidates. The pair conspired to pressure private companies to transfer about $65.5 million (61.9 million euros) to two nonprofits that Choi controlled, the indictment said. Auto giant Hyundai and telecommunications company KT were forced to contract millions in advertising business to Playground, an ad agency  run by Choi, the prosecutor said.

Park's term lasts until Februrary 2018. If she steps down before the presidential vote on December 20, 2017, an election must be held within 60 days.

jar/jlw (AP, dpa)