A South Korean court has sentenced Choi Soon-sil, a friend and adviser to former president Park Geun-hye, to 20 years in jail for corruption, influence-peddling and abuse of power, BBC reports.
Choi was at the heart of a massive corruption scandal that led to the impeachment of Ms Park, the country's first female president.
Ms Park is standing trial for more than a dozen charges but denies wrongdoing.
A lawyer for Choi said she will appeal the sentence.
Choi was accused of using her presidential connections to pressure conglomerates - including electronics giant Samsung and retail group Lotte - to donate millions of dollars to two non-profit foundations she controlled.
"The guilt of the accused is heavy," the judge said, adding that she had capitalised on her "long private ties" with Ms Park to solicit bribes and had "meddled in state affairs widely".