Xia Hong-bo, 35, was on duty when the 651-dwt Eifuku Maru No 18 (built 1992) capsized south of Tokyo on Friday after a collision involving Xia's 5,200-dwt Jia Hui (built 2005).
The crewman has been questioned on suspicion of professional negligence over the accident south of Tokyo on Friday.
Jia Hui was largely undamaged and its 13 mainly Chinese crew safe.
Eifuku Maru No 18 was heading from Nagoya to Ichikawa.
