Lee was indicted Tuesday on a string of charges, including bribery and embezzlement. He has been in custody since last month.

The special probe team suspects that Lee gave or promised some 43.3 billion won ($38.3 million) in kickbacks to Park's friend Choi Soon-sil in return for the government's backing of a merger of two Samsung affiliates in 2015.

The business merger was seen as critical to the smooth management succession of the group from ailing Samsung Electronics Chairman Lee Kun-hee to his only son Jae-yong.

Four other senior executives at Samsung -- Vice Chairman Choi Gee-sung and President Chang Choong-ki from the group's future planning headquarters and President Park Sang-jin and senior executive Hwang Sung-soo from the electronics giant -- will also undergo trial without detention.

It is unclear whether the defendants will appear in court, as it is not mandatory for them to attend a preparatory hearing. (Yonhap)