The de facto head of South Korea's Samsung Group, Lee Jae Yong, denies all charges against him, his lawyer said yesterday, at the start of what the special prosecutor said could be the "trial of the century" amid a political scandal that has rocked the country.

Lee's lawyer said on Thursday that the executive, now being detained at the Seoul Detention Center in South Korea, denies having any involvement in a political business scandal which has rocked the foundations of both Samsung and the country itself.

Lee, who is being detained at the Seoul Detention Centre, did not attend court.

The second preliminary hearing is set for March 23, while the date of the verdict's announcement has not been announced so far.

Song Wu-cheol, defending Lee, told the court that it was unclear what kind of order Lee is supposed to have given.

In the same scandal, South Korea's President Park Geun-hye had her powers suspended since her impeachment by parliament in December.

Samsung has constantly denied any wrongdoing.

President Park's fate is due to be decided on Friday when judges will decide whether to throw her out of office or reinstate her.

The special probe team suspects that Lee gave or promised 43.3 billion won (US$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.

Additionally, Samsung attorneys argued that numerous statements in the indictment of Lee were opinions of the prosecutor and not matters of fact.

According to the New York Times newspaper, the four other Samsung executives, allegedly involved in embezzlement, also denied the charges.