It has been mission impossible for 16 years: collecting 167.2 billion won in overdue fines from a former strongman who claimed to have only 290,000 won at hand and is notoriously at home with brinkmanship.

So, many observers were skeptical when the prosecution began a whirlwind investigation into former President Chun Doo-hwan’s family nearly four months ago with an aim to force him to pay the bill stemming from his misdeeds while in office in the 1980s.

Chun’s family finally announced Tuesday that they would pay the full amount, succumbing to persistent pressure from the prosecution and a growing public antipathy toward a former leader who continues to flout the law.

To the prosecution’s part, it was also a triumph politically. The investigation has somewhat muted public and political outcry for overhauling and weakening the powerful agency.

The feat may now be used to strengthen its argument for retaining its authority to take on cases involving top level figures in government, politics and the corporate world.

In May the prosecution launched a task force to collect overdue fines from Chun and conducted an intensive, two-track investigation into Chun and his family.

They did a search and seizure of Chun’s concealed assets, but soon turned to seeking ways to prosecute his family members, threatening Chun that his children could be sent to prison. Last month, the prosecution detained Lee Chang-seok, the younger brother of Chun’s wife Lee Soon-ja, on charges of evading about 5.9 billion won in tax

In the meantime, the prosecution had an unexpected surprise.

Former President Roh Tae-woo, Chun’s immediate successor, said he would voluntarily pay up his remaining fines of 23 billion won, apparently moved by the prosecution’s intensive probe into Chun’s entire family.

The prosecution’s victory of collecting overdue fines from the two disgraced presidents came at a time when it is under pressure to reform.

Calls have been mounting from both inside and outside of the prosecution to reform following a series of scandals involving bribes, sex and abuse of power. The elite law enforcement agency which wields exclusive rights to indictment in the country’s criminal justice system, has been resisting moves to put them in check.

Collecting fines from Chun is seen as an attempt by the prosecution to tighten discipline and win back the public’s support. The prosecution’s new chief Chae Dong-wook has ordered prosecutors to take every possible means to collect Chun’s concealed money and put an end to a seesaw game between the prosecution and Chun which started back in 1996.

Prosecutor general Chae was one of prosecutors who initially investigated and indicted Chun over charges of bribery, insurrection and attempted murder. Chae demanded a death penalty against Chun.

After President Park Geun-hye took the office early this year, the prosecution has been looking into highly sensitive cases, including the state spy agency’s alleged political intervention during the last presidential election. The prosecutor chief who drives the missions, however, is now under pressure from conservatives following a report he allegedly had a son out of wedlock through an extramarital affair.

By Cho Chung-un (christory@heraldcorp.com)