He Jiankui, the Chinese scientist who claimed to have created the world’s first gene-edited babies has gone missing after his former employees denied that he was detained over the weekend, the South China Morning Post reports.

He apparently hasn’t been seen publicly since he made an appearance at a scientific summit on Wednesday, a spokeswoman for his former workplace denied reports that he was being detained. Telling the newspaper “right now nobody’s information is accurate, only the official channels are.”

He said last week that he had altered embryos for seven couples during fertility treatments, and said that the embryos were born “normal and healthy”.