After questioning ousted President Park Geun-hye, at the core of a corruption scandal that has rocked the country, the prosecution is expected to quicken its investigation into local conglomerates and ex-Presidential Secretary Woo Byung-woo.

For now, the investigation team has not revealed details on how the remaining probe will go or who will be summoned. It is also keeping mum on whether Park will be arrested and which charges she additionally faces during the briefing Wednesday. 

“We are not in a stage to tell you (whether Park will be arrested),” an official from the prosecution said. “We will make a decision based on law and principle after thoroughly reviewing the investigation records.”

But speculation lingers that the prosecution will likely decide on the arrest by early next week and indict her in mid-April to minimize the impact the probe might have on the May 9 presidential election.

With Samsung Electronics Vice Chairman Lee Jae-yong already standing trial for giving bribes to Park and her friend Choi Soon-sil, the prosecution is to focus the investigation on other local firms, including SK and Lotte Group.

The firms are suspected of offering donations to the Mir and K-Sports foundations -- allegedly controlled by Park’s jailed friend Choi -- in return for the Park administration’s political favors.

SK allegedly sought to have its chief pardoned while Lotte Group looked to win a business license for its duty-free shop in exchange for the donations, which the prosecution suspects as bribery.

Woo is next in line. The prosecutor-turned-presidential aide is accused of condoning Choi’s meddling in state affairs and exerting undue influence over the prosecution to hinder a previous investigation into the Sewol ferry disaster in 2014. The Park administration was heavily criticized for its botched rescue operations during the accident, which left more than 300 dead or missing.

Park headed home in the morning after over 21 hours of questioning by the prosecution as a suspect on a total of 13 charges, including bribery, abuse of power and leaking of government secrets in connection with the corruption scandal.

“The probe went smoothly,” an official from the prosecution told reporters Wednesday. “She reviewed the statement in detail while consulting her lawyers. Park appeared to be cautious and meticulous.”

After entering the Seoul Central District Prosecutors’ Office at 9:25 a.m., the questioning went until 11:40 p.m. It took about seven hours for the ousted president to review statements she made during the interrogation.

She allegedly denied all charges, claiming no knowledge of Choi and her inner circle’s wrongdoings. She also actively defended herself, thoroughly reviewing the statements and asking the investigation team to revise them when needed.

The prosecution allegedly focused on grilling her over her role in coercing local firms to make donations to the Choi-controlled entities and giving them political favors in return, which could determine whether she will be charged with extortion, abuse of authority or bribery.

Park declined to comment as she left. She made an apology and vowed to the public to go through the process sincerely before heading into the interrogation room Tuesday.

“We express our respect to the prosecutors and their families who made efforts to reveal the truth,” said Park’s lawyers. They said the questioning proceeded in a “rational” and “calm” way, unlike the probe by an independent counsel who they denounced as “politically biased.”

The questioning came 11 days after Park became an ordinary citizen upon the Constitutional Court’s decision to remove her from office on March 10 over a corruption scandal. The ruling stripped her of the immunity that had shielded her from criminal investigation.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)