Seoul, Oct 26 (IANS): South Korea's prosecutors announced Wednesday they have begun investigating a corruption scandal and leaking of documents involving President Park Geun-hye.

Several reports in recent weeks have alleged influence peddling between President Park Geun-hye and Choi Soon-sil, a close friend and also the ex-wife of Park's former aide, and who allegedly used this connection to raise funds and even influence government decisions, Efe news reported.

"Regardless of the reasons involved, I am sorry that (the scandal) has caused national concerns," Park said on Tuesday evening in a televised address.

Meanwhile, the Seoul Central District Prosecutors' Office has conducted several raids of Choi's home and of nine nonprofits linked to her, the office announced on Wednesday.

Among them are the Mir and K-Sports foundations, suspected of having raised around 80 billion won ($70 million) with the help of the Federation of Korean Industries, the biggest employer in Korea.

Choi, who holds no official position and whose current whereabouts are unknown, is said to have used her influence to secure money earmarked for promoting globally the culture and sports of the country, for personal use.

Park also sent her official documents and drafts of dozens of presidential speeches to review, according to South Korean television network JTBC.

"During the last presidential election campaign, she (Choi) has offered me personal comments about my campaign activities, mostly speeches and publicity efforts," Park had said in her apology.

The scandal has caused Park's popularity ratings to drop to their lowest levels since she took office in 2013 and comes at a time when Park is pushing for a constitutional reform to increase the maximum period a president can hold office, from the current five years.