The court on Thursday rejected the prosecution’s request for warrants to detain an executive of Samsung Electronics’ after-sales service affiliate and two chiefs of its partner firms over their alleged attempts to sabotage labor union activities.

The executive of Samsung Electronics Service, surnamed Yun, is suspected of leading an operation to bring down the union from July 2013 to late 2015.

The Seoul Central District Court said it is “difficult to acknowledge the reasons and the need for the suspect’s detainment at this point, considering his status and role in the organized crime and the progress of the probe.”

The two others, surnamed Yoo and Doh, are suspected of carrying out Yun’s schemes by shutting down a service center where all the workers were unionized, and even paying off the family of a union member who killed himself while protesting Samsung’s sabotage attempts.

Prosecutors applied for writs against the three on Tuesday on charges of violating the law on labor unions and labor relations adjustment.

Prosecutors reopened the investigation into Samsung’s alleged attempts to disrupt union activities after finding related documents during raids of two Samsung Electronics buildings in February as part of a probe into bribery allegations against former President Lee Myung-bak.

The documents detail Samsung’s “masterplan” on how to hamper workers’ efforts to set up and operate unions.

Prosecutors have searched the headquarters and regional service centers of Samsung Electronics Service as well as the residences of those involved.

They also raided the office of the Korea Employers Federation last week on suspicions that Samsung used it to delay negotiations with a union of service center workers. The KEF was commissioned to carry out collective bargaining with the union of service center workers in 2014 on behalf of the service centers run by its partner firms.

The court’s dismissal of warrants for the three suspects has delayed the prosecution’s plan to expand the probe to those in senior positions at the after-sales service company, Samsung Electronics and Samsung Group.

Prosecutors plan to consider filing a second request for the warrants.

“It is difficult to accept the dismissal of warrants as we have secured most of the evidence through raids and inquiries,” a prosecution official said.

By Kim So-hyun (sophie@heraldcorp.com)