South Korean prosecutors have raided the offices of Samsung Electronics as part of a probe into the political scandal around President Park Geun-hye.
The prosecutors are investigating allegations that Samsung gave money to the daughter of Choi Soon-sil, a close friend of the president.
Ms Choi is accused of using their friendship to interfere in politics and solicit business donations.
Samsung confirmed the raids to the BBC saying they had "no further comment".
President Park has apologised for her ties to Ms Choi but faces mounting calls to resign.
In this latest twist of the scandal that's been rocking South Korea for weeks, prosecutors are investigating allegations that Samsung might have provided €2.8m euros ($3.1m, £2.5m) to a company co-owned by Ms Choi and her daughter, to bankroll the daughter's equestrian training in Germany.
Prosecutors are also reported to have raided the offices of the Korea Equestrian Federation and the Korea Horse Affairs Association.
Ms Choi was arrested on 3 November and charged with fraud and abuse of power.
Over the past days, tens of thousands of South Koreans have protested in the capital, Seoul, to demand the resignation of President Park over the corruption row.
Ms Choi, a long-time friend of Ms Park's, is the daughter of Choi Tae-min, a shadowy quasi-religious leader who was closely linked to Ms Park's father, then-president Park Chung-hee.
She is alleged to have pushed businesses to donate millions of dollars to foundations she controlled, helped choose presidential aides, and even picked the president's clothes.
Ms Park has since apologised on TV for allowing her long-standing friend inappropriate access to government policy-making. The president admitted she had let Ms Choi edit her speeches.
President Park has already replaced her prime minster, reshuffled her cabinet and dismissed several aides, but there are growing calls for her resignation or impeachment.
The scandal has left Ms Park with an approval rating of just 5%.
Choo Mi-ae, leader of the main opposition Democratic Party, said she did not believe the apology was genuine and called on her to accept a new prime minister recommended by parliament.
Ms Park became her country's first female president when she was elected in a close-run contest in December 2012.