China's imports of fish and shellfish from Japan fell to zero in September, Chinese customs authorities said Wednesday, after Beijing imposed a blanket ban on Japanese fishery products in late August.

The result followed a 33% decline in July from a year before and a 70% drop in August.

The Chinese government started to tighten its import restrictions on Japan around July due to Tokyo's plan to release treated water from its Fukushima No. 1 nuclear power plant into the ocean.

Beijing imposed the blanket ban on Aug. 24 immediately after the nuclear plant started releasing the treated water, which contains small amounts of radioactive tritium. China also said it would punish those who fail to comply with the measure.

Meanwhile, China's imports of fish and shellfish from Hong Kong shot up 54 times in September from a year before and those from South Korea and Taiwan grew significantly as well. The figures suggest that Japanese products may be being sent to China indirectly.

Earlier this month, Russia introduced restrictions on imports of Japanese fishery products, joining the Chinese measure.