The Corruption Investigation Office for High-ranking Officials is weighing whether to investigate a lawmaker affiliated with the main opposition People Power Party for allegedly receiving illegal political support funds.

If conducted, it would be the first official investigation of an incumbent lawmaker by the CIO.

Last week the anti-corruption watchdog asked the North Gyeongsang Province branch of the National Election Commission to send over related documents and other data on a main opposition lawmaker who was not identified, the CIO said Wednesday.

The request was made as part of a preliminary inspection to verify whether the case warrants a formal CIO investigation.

The lawmaker allegedly received 20 million won ($17,300) from a former municipal council member and her family in 2016 and 2017, accepting four payments of 5 million won each. The funds were reportedly in exchange for influencing the party to support the municipal council member’s 2018 election campaign.

The Political Funds Act states that an individual can donate up to 5 million won a year in support of a lawmaker. In this case, it is suspected the council member split her contribution into four payments to evade law enforcement scrutiny.

An NEC branch in the lawmaker’s precinct reported the case to the prosecution in May 2020, and the council member was fined 12 million won in April.

But the prosecution did not indict the People Power Party lawmaker, instead accepting her explanation that she was unaware that people associated with the council member had donated additional funds.

The funds are said to have been returned to the donors after the lawmaker became aware of the issue.

Since its launch in January, the CIO has been involved in a number of cases but has never directly investigated a lawmaker as a criminal suspect. Yet even if the agency finds enough evidence to indict the lawmaker it will not be able to do so -- the authority to indict is still exclusively in the hands of the prosecution.