Unionised workers at DSME have prevented a team from Hyundai Heavy Industries (HHI) carrying out due diligence ahead of their $1.6bn merger.
The on-site inspection was called off in Geoje, Korea, on Monday, the Yonhap news agency reported.
HHI officials were denied entry, as were executives from Korea Development Bank, which is selling its DSME stake to HHI.