The Seoul Central District Prosecutors' Office sent investigators to Samsung Electronics headquarters to search and secure documents and computer hard discs relevant to the allegations.
Samsung was suspected of having been deeply involved in its repair service unit's sabotaging of workers' efforts to establish a labor union. The unit's labor union was set up in 2013.
The South Korean tech behemoth has been under fire for its nonunion policy. The workers-friendly government of South Korean President Moon Jae-in has gravely dealt with the sabotaging attempt.
State prosecutors searched Samsung offices on May 24 and sought arrest warrant for the head of the repair service unit, which was dropped twice by the court.
Two other suspects involved in the allegations have been arrested recently, encouraging prosecutors to search the head office of Samsung again.
Samsung Group, the country's biggest family-controlled conglomerate, has been embroiled in controversy after Lee Jae-yong, an heir apparent to Samsung, was set free in February with a suspended jail term in the second trial.
Lee was charged with bribing former South Korean President Park Geun-hye who was impeached and jailed over a series of corruption and abuse of power.