Samsung Electronics vice chairman Lee Jae-yong has been called for questioning by special prosecutors for a second time as part of investigations into the bribery scandal involving South Korea's president. Two company executives have also faced questioning on the same day.
Lee, de facto boss of the entire Samsung business group, was last month questioned for 22 hours as a suspect in the scandal. His arrest warrant was then rejected by a South Korean court for "lack of reasoning".
Lee faces charges of bribery and embezzlement for allegedly orchestrating or knowing about bribes paid by Samsung Electronics to Choi Soon-shil, a friend of President Park Geun-hye, to get support for a controversial merger.
Prosecutors have been gathering more evidence against Lee since the court's rejection of the arrest last month. Several Samsung executives have been interviewed since then.
They now believe Samsung influenced the Fair Trade Commission (FTC) to further support the merger.
Investigators will decide whether to file for another arrest warrant this week after the interrogation.
Samsung has consistently denied bribing the now imprisoned Choi, saying that it is a victim of extortion by President Park, who was impeached since the scandal broke out.