The public’s trust in prosecutors -- already quite low -- has sunk further as a senior prosecutor has been found to have told lies in the process of clarifying how he earned huge stock trading gains last year.

Jin Kyung-jun, the commissioner of the Korea Immigration Service under the Ministry of Justice, drew attention in March when the Government Public Ethics Committee disclosed the personal wealth of high-ranking government officials.

Jin ranked sixth among the 1,813 senior government officials by registering about 15.7 billion won ($13.2 million), with 12.6 billion won coming from sales of his shares in Nexon Corp., one of Korea’s top game developers. 

Jin said he disposed of his 800,000 Nexon shares, which he had acquired for 425 million won in 2005. Questions arose over how he could obtain the shares, as at the time, the high-flying company’s stock was unlisted and therefore hard to acquire for ordinary investors.

The ethics committee, which has been probing allegations that Jin illegally acquired the shares using insider information, said Sunday it could not find any evidence the prosecutor had broken the law in obtaining them.

But the committee has found that Jin lied twice about how he financed his acquisition of the Nexon stock. The prosecutor at first said he had bought the shares with his own personal money.

Then, he told the committee in April that he had borrowed 200 million won from his mother-in-law. The committee, however, has found that the loan took place six months after Jin had acquired the stock.

Jin finally confessed that the money he used to purchase the shares came from Nexon. He added he paid back the money to the company without any interest.

Following his confession, Nexon also admitted it had provided him with the money. The company said it helped Jin and two other acquaintances of its chairman, Kim Jung-ju, acquire its shares to prevent them from being owned by a hostile company.

In early April, Jin offered to resign from his post as allegations of misconduct mounted against him. The government did not accept his resignation, saying that he should first face a probe by the ethics committee.

Now that Jin has been found to have lied, the government should fire him instead of accepting his resignation. 

Separate from the probe by the ethics committee, prosecutors have to thoroughly investigate the stock transaction between Jin and the Nexon chairman, who are both graduates of Seoul National University.

A civic group has already filed a complaint against the two, arguing that the Nexon stock Jin acquired should be seen as a form of bribery. 

Prosecutors need to find out whether Jin used his influence in cases filed against Nexon after obtaining the company’s shares. He could be punished for taking bribes if he is found to have wielded his influence on cases involving the game developer.