Japan's fisheries agency said on Saturday fish tested in waters around the wrecked Fukushima nuclear plant did not contain detectable levels of the radioactive isotope tritium, Kyodo news service reported.
Nets were set up on Thursday when plant operator Tokyo Electric Power Company (Tepco) 9501.T began releasing treated radioactive water into the Pacific, angering fishermen and many others in Japan, alarming consumers in neighbouring countries and prompting China to ban Japanese aquatic products.
The agency plans to announce test results daily. Tepco said on Friday seawater near the plant contained less than 10 becquerels of tritium per litre, below its self-imposed limit of 700 becquerels and far below the World Health Organization's limit of 10,000 becquerels for drinking water.
Calls to the fisheries agency for comment were not answered on Saturday.
After a lengthy debate, the government of Prime Minister Fumio Kishida decided on Tuesday to allow the release of 1.3 million tons of treated water from the Fukushima plant, destroyed by a 2011 tsunami because Tepco was running out of storage space.
The utility filters most radioactive elements out of the water but dilutes tritium, an isotope of hydrogen, which is difficult to separate from water.
Prince Harry said on Friday that he wanted reconciliation with the British royal family but his father King Charles will not speak to him over a row over his security and he did not know how long the monarch, who has cancer, would live.
A magnitude 7.4 earthquake struck Drake Passage between Cape Horn and Antarctica at a depth of 10 km (6 miles) on Friday, the United States Geological Survey said.
A ship with humanitarian aid and activists for Gaza was bombed by drones while in international waters off Malta early on Friday, its organisers said, and the Maltese government said after a rescue operation that everyone on board was safe.
A power outage hit several regions of Indonesia's resort island of Bali on Friday and efforts were underway to restore services to those affected, state utility Perusahaan Listrik Negara said.
A Russian drone attack late on Thursday set buildings ablaze in Ukraine's southeastern city of Zaporizhzhia, injuring 29 people, regional governor Ivan Fedorov said.