Hong Kong (CNN) One of five Hong Kong booksellers who went missing in late 2015 said Thursday he was kidnapped after crossing the border into mainland China.

Defying China, Lam Wing-kee, who resurfaced earlier this week, spoke publicly about his detention by Chinese authorities at a surprise news conference, according to Hong Kong public broadcaster RTHK.

Lam said he was taken by "special forces" after crossing the border into mainland China from Hong Kong eight months ago and detained in a small room. A confession he made on Chinese state television was scripted and edited, he added.

He said he had been told to return to mainland China on Friday with evidence about to whom his bookstore had been sending banned books. But he said he had decided not to go back and wanted to speak out about what had happened.

"I had to be very courageous. I thought about it for two nights before I decided tell you all what happened, as originally and completely as I could," he said, according to a transcript translated by the South China Morning Post.

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