The special investigative unit of the Seoul Central District Prosecutors’ office stormed the Samsung headquarters in Gangnam district on Wednesday morning, Xinhua news reported.
Samsung is suspected of donating tens of millions of US dollars to two non-profit foundations controlled by Choi Soon-sil, President Park Geun-hye’s longtime confidante.
The company was seeking favours in the merger of its two subsidiaries.
Allegations include Samsung’s wire transfer of 2.8 million euros to a German company owned by Choi.
Investigators have seized materials on the merger of Samsung C&T and Cheil Industries in 2015.
Prosecutors also raided the headquarters of the national pension fund operator.