SEOUL (Reuters) - The woman at the center of a corruption scandal gripping South Korea angrily protested her innocence on Wednesday, shouting that she had been made to confess as she was forcibly summoned for questioning.

Choi Soon-sil, who has been indicted for meddling in state affairs through her friendship with impeached President Park Geun-hye, made the protest at the special prosecutor’s office, before being pushed into an elevator by correctional officers.

The dramatic scenes came as the outgoing chief judge of the Constitutional Court urged the bench to wrap up Park’s impeachment trial by March 13, when the retirement of another judge will reduce the nine-judge court to seven and could raise questions about the verdict.

His comments were the clearest indication of the timing of a decision on Park, either to remove her from office with an election to be called 60 days later, or for her to be reinstated.

Park was impeached amid the influence-peddling scandal that has engulfed her administration over recent months. If the impeachment is upheld, she will become the first democratically elected leader to be removed from office.

Choi was brought into the special prosecutor’s office on an arrest warrant after refusing to answer several summons.

“I am being forced to confess committing crimes jointly with the president,” she shouted to reporters. “I don’t deserve to be treated like this. And my baby and my grandson,” she said as guards pushed her into the elevator.

The special prosecutor’s office dismissed her protests.

“Regardless of such groundless claims of hers, the special prosecutor will thoroughly carry out the investigation by law and principle,” office spokesman Lee Kyu-chul told a regular briefing, adding that Choi was trying to discredit the investigation.

Choi Soon-sil, the woman at the centre of the South Korean political scandal and long-time friend of President Park Geun-hye, arrives for a hearing arguments for South Korean President Park Geun-hye's impeachment trial at the Constitutional Court in Seoul, South Korea, January 16, 2017. REUTERS/Kim Hong-Ji

As part of their investigation, prosecutors are looking into Samsung Group’s [SAGR.UL] sponsorship of the equestrian riding career of Choi’s daughter, Chung Yoo-ra, 20, who was arrested in Denmark after being sought by South Korean authorities.

Chung has been accused of criminal interference related to her academic record and other unspecified charges.

Park was impeached by parliament in December after accusations that she colluded with Choi to pressure big businesses, including Samsung, to donate to two foundations set up to back the president’s policy initiatives.

Park, 64, remains in office but has been stripped of her powers while she awaits her fate.

Park, Choi and Samsung have all denied wrongdoing.

Prosecutors said on Wednesday they had summoned Samsung Group President Kim Jong-joong and Samsung C&T Corp 028260.KS President Kim Shin for questioning as witnesses.

The prosecution has now summoned seven different executives at Samsung Group or an affiliate of the country’s top conglomerate and have so far identified two of them – leader Jay Y. Lee and Samsung Group Vice Chairman Choi Gee-sung – as suspects in the widening graft scandal. Chief Judge Park Han-chul, who retires on Jan. 31, urged the Constitutional Court to wrap up the impeachment trial by March 13, when the retirement of another judge will reduce the nine-judge bench to seven.

Speaking on the ninth day of the hearing, the chief judge said the retirement of two judges may distort the impartiality of the court.

“If another judge’s seat is vacated, that is not just a matter of one vacated seat but could distort the outcome of the decision,” he told a public hearing.

The court has previously stressed the need to balance a speedy resolution of the crisis with proper deliberation, but this was the first time the court has mentioned a specific timeline.

Seven sitting judges are the minimum required by law to rule on an impeachment, with six needed to vote to uphold the motion for Park to be removed.

Sources with intimate knowledge of the court’s inner workings told Reuters that seven judges, for a landmark ruling such as this, were too few and could invite questions of the ruling’s legitimacy, especially if it is not unanimous.

The sources declined to be identified due to the sensitivity of the matter.