A total of 18 people have been arrested after cooking up stories and spreading fake news about “plastic seaweed.”

In February 2017, a number of videos were spread online, intended to fan rumors that some seaweed on the market was made of plastic. The rumors caused economic losses for the seaweed industry and a public panic over food safety. The rumor was later refuted by the China Food and Drug Administration at a press conference held by the State Council on Feb. 27.

About a month ago, a 32-year-old man surnamed Wang from Jinjiang, Fujian province recorded a video clip claiming that the seaweed produced by a local company was really made of plastic.

He blackmailed the company and threatened to make more videos if they ignored his demands. Wang was soon arrested after the company reported the case to police.

So far, a total of 18 people have been arrested in connection with this fake news story, said Zhang Hongye, deputy director of the Cyber Security Defense Bureau of the Ministry of Public Security. Jinjiang's government conducted a special inspection of seaweed at a local market, examining the products of 55 companies implicated in the rumors. No evidence of counterfeit or adulterated products was found.

A 42-year-old woman surnamed Zeng from Guigang, Guangxi Zhuang Autonomous Region also recorded a video in which she tested seaweed at home and claimed that it was made of plastic. She then sent the video to a chat group in a mobile social application. She didn’t realize that her action resulted in a huge loss for the seaweed company - cancellation of 18 orders that totaled 4.68 million RMB ($688,884) - until local police informed her. Now, she is suspected of damaging a commodity's reputation.

“Further efforts will be made to fight rumors related to food safety, and those involved will be severely punished,” Zhang said.