Prosecutors detained Lee Jong-chan, senior executive vice president of the state-run Korea Electric Power Corp., on Tuesday as part of a probe into a corruption scandal involving the company, parts suppliers and certifiers.

Busan District Prosecutors’ Office is looking into allegations that JS Cable, a signal cable supplier, colluded with Saehan Total Engineering Provider Co., a certifier suspected of forging test certificates for parts used in nuclear reactors. Officials from KEPCO and its subsidiaries are alleged to be deeply implicated in the case.

The prosecution said that a court issued a warrant against the 53-year-old executive on the same day.

Lee, who heads KEPCO’s overseas business division, allegedly conspired with parts suppliers and certifiers to falsify test certificates of parts for atomic reactors five years ago. Lee was a deputy director of an electricity generation division at Shin-Kori Nuclear Power Plant in 2008 and was promoted to head of the plant a year later.

Lee is suspected of approving subpar signal cables at that time, despite knowing the certificates for the parts were problematic. Sources say that the prosecution arrested Lee after his subordinate surnamed Song confessed that he told Lee that the signal cable had failed to pass the safety tests.

In June, the prosecution arrested and indicted two mid-level officials including Song for conspiracy and fraud. Song is suspected of ordering technicians at KEPCO Engineering and Construction to approve signal cables.

The prosecution has been widening its investigation to upper-level officials, in the belief that the two mid-level officials were not in a position to make such decisions.

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