Opposition leader Lee Jae-myung appeared at the prosecutor's office to be questioned as a suspect Saturday in connection with allegations over a property development project.

It was the second time for the chair of the majority opposition Democratic Party of Korea to appear before the prosecutor for questioning after being interrogated in a separate corruption probe 18 days earlier.

The questioning started at 10:30 a.m. and ended at 9 p.m., then Lee reviewed the interrogation report on him and left the prosecutor's office at 10:53 p.m. However, the actual interrogation time except for lunch and dinner was about 8 hours. He refused a late-night questioning.

The prosecution suspects Lee of being at the heart of the allegations. They involve a private asset management company, Hwacheon Daeyu, that reaped about 404 billion won ($328.7 million) of profits from the development project in Daejang-dong in Seongnam, thanks to dubious arrangements allegedly approved by then Mayor Lee. He is suspected of breach of trust.

Lee submitted to the prosecutor a 33-page "statement" categorically denying any allegations against him. He effectively used his right to remain silent in response to the prosecutor's questions. The prosecution prepared a questionnaire that was more than 100 pages, but he is said to have repeated "the statement substitutes my answer" to most of the prosecutor's questions. In effect, he refused to make an oral statement.

Earlier, he had done the same thing when questioned by the prosecution on Jan. 10 in connection with allegations that a professional football club owned by the city under Mayor Lee received illegal donations -- bribes in other words -- from Seongnam-based business establishments in exchange for the city doing them favors.

He effectively exercised his right to remain silent on both occasions of the prosecutor's interrogation of him.

What is the point of appearing before the prosecutor for questioning? His silence indicates that he has no intention to cooperate with a reasonable investigation to find the truth.

Outside the prosecutor's office, he claimed that justice will prevail and vowed to fight against the prosecutors. But when he was really given a chance to refute the prosecutor's case for indicting him, he held his tongue. If Lee believed he was falsely accused, he should have tried to vindicate himself, rather than remaining silent.

Of course, a suspect can exercise their right to silence as a legitimate self-defense tool, but silence is likely to solidify suspicions. If a suspect believes he or she is innocent, it is common sense to actively cooperate with investigation. Lee's silence only increases suspicions that he is trying to hide something or to prevent his lies from being discovered if he speaks out. Few believe that the prosecution is trying to manipulate the case as he argues.

Lee was originally notified by the prosecution of the summons to come to the prosecutor's office twice, on Jan. 27 and Jan. 30, but he came to the office on Jan. 28 -- and one hour late at that. Lee refused late-night questioning. This has led the prosecution to run short of time for a face-to-face interrogation of him.

The prosecutor, saying additional interrogation is needed, demanded Lee show up at the prosecutor's office again for questioning, but he is said to have returned home without a clear reply to the demand. He said on Monday that although "it is humiliating and unfair," he will go again to the prosecutor’s office "as a loser (of the presidential elections)" because the prosecution asked him to come again.

Naturally, a suspect is supposed to answer a summons from the prosecution, but Lee speaks of the situation as if he is an innocent victim to the prosecution’s malicious subpoena. He shifts blame to the prosecution. The prosecution did not summon him because he lost the presidential election.

It is unheard of for a suspect to try to decide not only on the day he is to appear for questioning, but also on the duration of the interrogation and the number of times he is to be summoned. This is unimaginable in the eyes of the general public. Lee's behavior ignores the rule of law and judicial procedures.