Min Kyung-kwon, head of a shareholder advocacy group representing individual investors, speaks during a press conference near the National Assembly in Seoul, June 1. Yonhap

A shareholder advocacy group representing individual investors on Wednesday filed criminal complaints against the chief executives of Samsung Electronics and SK hynix, claiming profit-linked bonus agreements reached with labor unions were unlawful.

The group, whose name translates roughly as the "Republic of Korea Shareholder Activism Headquarters," filed police complaints accusing SK hynix CEO Kwak Noh-jung, Samsung Electronics Vice Chairman Jun Young-hyun and CEO Roh Tae-moon of breaching their fiduciary duties to shareholders.

It also filed a complaint against Labor Minister Kim Young-hoon with the Corruption Investigation Office for High-ranking Officials, alleging he abused his authority by intervening in Samsung's wage negotiations in May.

Speaking at a press conference, Min Kyung-kwon, head of the group, argued that performance bonuses tied to corporate earnings should be treated as profit distributions, and thus should not be subject to collective bargaining.

"Any profit-sharing arrangement should require shareholder approval, rather than being negotiated through collective bargaining," Min said.

He accused Samsung's management of signing a bonus agreement that created "a major outflow of corporate assets" by compromising with what he called an "unlawful demand" by the company's labor union.

Min also alleged that the labor minister pressured Samsung to reach the bonus payout agreement.

The complaints stem from a wage agreement reached between Samsung Electronics and its labor union on May 20, about 30 minutes before a planned strike.

Under the agreement, mediated by the labor ministry, the company agreed to provide employees with a special performance bonus equivalent to 10.5 percent of business performance earnings.

Regarding SK hynix, the civic group argued that Kwak breached his fiduciary duties by implementing a bonus scheme that allocates a fixed share of operating profit to employees despite facing no strike pressure.

SK hynix last year scrapped a 1,000 percent base salary bonus cap and tied bonuses to 10 percent of its operating profit.