A flower grower in Fujisawa, Kanagawa Prefecture, unknowingly grew 722 illegal opium poppies and 401 were shipped to dealers in seven prefecture by mistake, according to Kanagawa.

As of Wednesday, 204 of the shipped flowers had been confiscated, as well as 321 still at the grower's, according to Shunichi Kondo of Kanagawa's pharmaceutical division. The rest are unaccounted for.

According to Kanagawa officials, the poppies were sold to flower dealers in Tochigi, Gunma, Saitama, Chiba, Tokyo, Kanagawa and Nagano prefectures.

A flower dealer in Nagano Prefecture is said to have sold the flower seeds purchased by the Fujisawa grower, who claimed to be unaware that the seeds were illegal.

The Fujisawa farmer asked the prefectural government if the seeds were banned. But officials at Kanagawa's agricultural technology center failed to correctly identify them and gave approval to the farmer, Kondo said.

Kanagawa launched an investigation after a citizen reported what appeared to be an illegal poppy being sold at a flower shop in Tokyo.

Japan, which witnessed China's 19th-century struggles in the Opium War, strictly bans the production and sale of opium-producing poppies.