Authorities in the central Vietnamese province of Quang Nam have admitted it is not easy to specify what breach of law has taken place when a local man made up a story about a mermaid caught by fishermen and circulated it online last week.

Pham Dac Hau was summoned by internal security police on Wednesday after he was identified as the administrator of the quangnamonline.vn, now inaccessible, and the writer of the false story, which had gone viral since it was published on Sunday.

Pham Hong Quang, director of the provincial Department of Information and Communications, said on Thursday his agency is “still trying to figure out” how to penalize Hau, who already confessed to having founded the erstwhile quangnamonline.com.vn website.

“Hau admitted his wrongdoing and had removed both the article and the website,” a department inspector told newswire VnExpress. “He said the made-up story was only created for fun.”

VnExpress also quoted a police source as saying that it is difficult to accuse the mobile phone repairman of any violations to determine a punishment.

“The website was his personal page so he did not have to seek a permit to run it,” the source said.

“We have reviewed many legal documents, none of which regulate such a situation so we are very confused.”

On Sunday, Hau posted a new article on his website, saying that Quang Nam fishermen had caught a 48kg mermaid, who they had found “occasionally enjoys sunbathing on nearby rocks,” with anesthetics and fishing nets.

The false story even came with a photo, showing what looked like a mermaid inside a green fishing net, with the writer claiming that she was also admitted to a nearby hospital for treatment, “pending studies by U.S. scientists.”

The article also quoted one of the fishermen as saying that a Japanese moneybag had asked to pay US$1 million to buy the legendary aquatic creature, but the offer was rejected.

Weird as it might be, the story was still shared on Facebook by many, who apparently believed that the legendary creature did exist in their country.

Hau later told police that he had used a photo from a wedding album of a couple in Hanoi and made up the mermaid story to “create some fun.”

The wedding album was produced as a story of an adventurer who rescues a mermaid when she is stuck in fishing nets, and later marries her.