South Korea's president offered a surprise public apology on Tuesday after acknowledging her close ties to a mysterious woman at the center of a corruption scandal.

President Park Geun-hye's apology came a day after a South Korean TV network, JTBC, reported that the woman, who has no government job, was informally involved in editing some of Park's key speeches. Other media have speculated that the woman, Choi Soon-sil, might have meddled in other state affairs.

Park's approval ratings have plummeted to a record low amid weeks of media reports that Choi might have used her connections to Park to push companies to make tens of millions of dollars in contributions to establish two nonprofit foundations.

In a nationally televised speech, Park said that Choi helped her on speeches and public relations issues during her 2012 presidential campaigning and after her 2013 inauguration. Park said she eventually stopped getting such help from Choi, but didn't say when that help stopped.

"To me, it was something that I did out of a pure intent to do things more thoroughly, but regardless of any reason, I am sorry that I caused concern to the people of our nation, caught them by surprise and hurt their feelings," Park said, bowing deeply.

Park didn't mention Choi's corruption allegations, but there was a frenzied social media reaction in South Korea over the president's acknowledgment.

Choi is a daughter of a Christian pastor who had worked as Park's mentor before his 1994 death, according to South Korean media reports. The pastor, Choi Tae-min, was originally a Buddhist monk, had six marriages and allegedly used his relationship with Park to take bribes from government officials and businessmen, the reports said.

The junior Choi is also the ex-wife of a man who served as Park's chief adviser when she was in the National Assembly before she became president in February 2013. A Japanese newspaper reported that Park was with the husband during a deadly ferry sinking in 2014 that killed more than 300 people, mostly teenagers. South Korean prosecutors charged the journalist from the Sankei Shimbun newspaper who wrote the story with defaming Park, but a Seoul court later declared him not guilty.

Park is the daughter of late dictator Park Chung-hee, who was assassinated by his own intelligence chief during a late-night drinking party in 1979. Wednesday marks the 37th anniversary of Park Chung-hee's death.