A South Korean judge questioned Samsung Group leader Jay Y. Lee behind closed doors on Wednesday to decide whether he should be arrested over his alleged role in a corruption scandal that led parliament to impeach President Park Geun-hye.

Lee, 48, in dark overcoat and purple necktie, did not answer questions from reporters as he left the Seoul Central District Court after the nearly four-hour hearing and headed by car to a detention centre to await his fate.

One of the five attorneys representing Lee struck a positive tone, saying the legal team had argued its case sufficiently.

"We are confident the court will make a wise decision," attorney Song Wu-cheol told reporters.

The special prosecutor's office on Monday said it would seek a warrant to arrest the third-generation leader of the country's largest conglomerate on suspicion of bribery, embezzlement and perjury.

Lee, who has been the de facto leader of South Korea's biggest conglomerate since his father Lee Kun-hee was incapacitated by a 2014 heart attack, was questioned last week for 22 straight hours at the prosecutor's office in Seoul.

He has denied wrongdoing.

Park, 64, was impeached last month by parliament over the influence-peddling scandal, a decision that if upheld by the Constitutional Court will see her become the country's first democratically-elected leader forced from office early.

Park, who remains in office but stripped of her powers while the court decides her fate, has denied wrongdoing.

The judge may not announce his decision on the arrest warrant for Lee until after midnight, a court official told Reuters on Tuesday. The court ordered Lee to be held at the Seoul Detention Centre, a half-hour drive away, while it reviews the warrant request.

The special prosecutor has accused Lee of paying bribes totalling 43 billion won ($36.70 million) to organisations linked to Choi Soon-sil, a friend of the president who is at the centre of the scandal, to secure the 2015 merger of two affiliates and cement his control of the family business.

Earlier this week, the special prosecutor indicted the chairman of the National Pension Service (NPS), the world's third-largest pension fund, on charges of abuse of power and giving false testimony.

NPS chairman Moon Hyung-pyo was arrested in December after acknowledging ordering it to support the controversial $8 billion merger in 2015 of the two Samsung Group affiliates while heading the health ministry, which oversees the NPS.

The special prosecutor's office has said it did not seek arrest warrants for three other Samsung Group executives that also underwent questioning, in order to minimise the impact on Samsung business.

The group's flagship, Samsung Electronics, is the world's biggest maker of smartphones, flatscreen TVs and memory chips.