Japan has released a Chinese fishing boat captain whose arrest two weeks ago sparked the worst row between the nations in years, Japanese media reports say.

Prosecutors earlier on Friday cited the damage already done to relations with Beijing as a factor behind their decision to free Zhan Qixiong, who was taken into custody more than two weeks ago, the reports said on Friday.

Japanese authorities detained Zhan after his trawler collided with two Japanese coast guard vessels near a string of contested islands in the East China sea on September 8.

The uninhabited islands, known as Diaoyu in China and as Senkaku in Japan, lie in an area with rich fishing grounds. The area is believed to have sizable oil and gas deposits. The islands are also claimed by Taiwan.