The other woman is still pregnant and will be kept under close observation by provincial health authorities.
He embraced the tool, called CRISPR, and past year rocked an worldwide conference with the claim that he had helped make the world's first gene-edited babies, despite a clear scientific consensus that making genetic changes that could be passed to future generations should not be attempted at this point.
His announcement was met with condemnation from hundreds of Chinese and worldwide scientists, who said any application of gene editing on human embryos for reproductive purposes was unethical.
Authorities also confirmed that He forged an ethical review between March 2017 and November 2018, and recruited eight couples to participate in the experiments, two of which achieved fertilization; twins Lulu and Nana are now under observation by Chinese medical experts, while another embryo has yet to be born.
China's official news agency said Monday that investigators in Guangdong province determined that the scientist, He Jiankui (HUH JEEN-qway), for the sake of fame evaded supervision of his work and violated research norms.
He used gene-editing technology known as CRISPR (short for Clustered Regularly Interspaced Short Palindromic Repeats).
The safety and efficacy of the technologies He used are unreliable and creating gene-edited babies for reproduction is banned by national decree, the report said. He was an associate professor at SUSTech, one of the top-ranked research universities in China.
The scientist, He, could not be reached for comment.
Many scholars pointed to a 2003 guideline that bans altered human embryos from being implanted for the goal of reproduction, and says altered embryos can not be developed for more than 14 days. The report said He acted alone and will be punished for any violations of the law, although it didn't say which regulations he may have broken.
Speaking at the genome summit in Hong Kong in November, He said he was "proud" of altering the genes of the babies, given the stigma affecting AIDS patients in the country.
Xinhua said He raised funds independently and privately organised a team of people to carry out the procedure, adding that he had forged ethical review papers in order to enlist volunteers for the procedure.
Chinese authorities also denounced He and issued a temporary halt to research activities involving the editing of human genes.
Prof He also explained that eight couples - comprised of HIV-positive fathers and HIV-negative mothers - had signed up voluntarily for the experiment.
"Those who are suspected of committing crimes will be transferred to the public security department", Xinhua reports.
This is not the first time Chinese researchers have experimented with human embryo technology.