The ship returned to Japan and MOL said readings showed radiation levels were very low.
Chinese authorities detected a maximum of 3.5 microsieverts per hour on the ship when it arrived, MOL said. "That level is above the global average of naturally occurring background radiation, but half of the radiation experienced on a Tokyo-New York flight,'' the line added.
Germany's second biggest shipping company Hamburg Sud decided at short notice to cancel the port call in Tokyo of its vessel Cap Isabel last Wednesday because of radiation concerns.
"An appropriately large time window must be available to any vessel calling in Japan for it to leave the region quickly if the situation in Fukushima should escalate further," explained Eva Graumann, director, corporate communications, for Hamburg SŸd.
Hamburg Sud it would continues to keep a close eye on the situation in Fukushima in order to be able to reach a timely decision on the next port calls in Tokyo and Yokohama.
Japan said last Thursday its Fukushima Daiichi nuclear plant that was crippled by the quake and the tsunami last month could not be saved and would have to be scrapped.