Japan's coastguard says its search-and-rescue mission for 40 missing crew from a capsized cattle ship in the East China Sea remains suspended, with no timing set for resumption.

So far, two crewmen have been rescued, while another died after being found unconscious on Friday.

Their ship, the Gulf Livestock 1, had sent a distress call from the west of Amami Oshima island in southwestern Japan last Wednesday as Typhoon Maysak lashed the area with strong winds and heavy seas.

The search was suspended due to bad weather on Saturday, as Haishen was headed towards southwestern Japan, having left the New Zealand port of Napier bound for China.

On board were almost 6000 live cattle and 43 crew - including two Australians and two New Zealanders.