South Korea's embattled president on Friday apologized to the nation over a snowballing political crisis involving a secret aide, and said she would submit to an investigation "if necessary," as her approval ratings dropped to the lowest recorded since democracy arrived here.

Park Geun-hye, who made history four years ago when she became the country's first female leader, is now facing the worst crisis of her turbulent tenure. A growing number of politicians and ordinary people are calling for her resignation, and her own justice minister has raised the possibility that she could be investigated for wrongdoing.

"I deeply apologize to the nation for causing this disappointment and distress," Park said Friday morning in a nationally televised address, only her second statement on the issue since the controversy erupted last month. Her voice was breaking during the statement, and she appeared to be on the brink of tears.

"I blame myself for everything. This is all my fault and I take full responsibility," she said in an attempt to quell public fury over the controversy.

The crisis began when local media reported that the notoriously aloof Park had been relying on Choi Soon-sil, a longtime confidante with links to a questionable shamanistic cult, for secret advice on everything from speeches to her wardrobe.

More evidence has since emerged that Choi, who held no official position and had no security clearance, had access to confidential information and a surprising amount of sway over the president, leading to local media outlets calling her the "shadow president."

In an emotional address Friday, an ashen-faced Park appealed to the public for sympathy, saying she had been living a "lonely life" in the presidential Blue House and had relied on Choi for friendship and guidance.

"Choi stood by me when I was going through a tough time and I let my guard down," Park said, adding that she "cannot sleep at night."

"I'm in great pain, even thinking about why I became the president," Park said. "I have tried so hard to be genuinely helpful to the people, but the result turned out to be the opposite and it breaks my heart."

Park also denied rumors that she was involved in any cult or had performed shamanistic ceremonies at the Blue House, saying such reports were "groundless."

Choi is also alleged to have taken advantage of her relationship with Park to enrich herself - she is accused to siphoning off much of the $70 million donated to foundations she ran - and benefit her family. Speculation that the rules were changed to allow Choi's daughter to enter a prestigious university contributed to the college president's resignation.

Choi is now in custody and a court has issued a warrant for arrest on charges of being an accessory to an abuse of power and attempted embezzlement.

Park also apologized for this part, saying that the businessmen who donated to the foundations did so for the right reasons.

As the scandal mounted, Park last week appeared on television last Tuesday to apologize and explain that Choi, whom she's known for 40 years, helped her through "difficult times." But as new information comes to light, the public is becoming more and more enraged.

Thousands of people protested in central Seoul last weekend calling for her resignation, and recent polls show as many as 70 percent of respondents want Park to stand down. Her approval ratings have sunk below 10 percent. Gallup Korea's daily poll Friday put Park's support at 5 percent, the lowest ever recorded for any South Korean president.

Park has attempted to quell the outrage by firing key ministers and advisers, but this has not had its desired effect. Both her justice minister and her nominee for prime minister have said that it is possible Park will be investigated for wrong-doing.

The constitution states that the president cannot be prosecuted while in office, but some legal scholars are saying it doesn't rule out investigation.

"I believe we can conduct an investigation into Park," Kim Byong-joon, Park's pick for prime minister, told reporters Thursday. "Everyone is equal before the law."

In her address Friday, Park said she was willing to answer questions.

"The prosecutors office should not be distracted. They should try to uncover the truth," she said. "I will do my best to clarify this case and I have already instructed my secretaries to actively cooperate with the investigation. If it is necessary, I myself will accept being investigated by the prosecutors' office, or even a special prosecutor's investigation."