He Jiankui: China condemns 'baby gene editing' scientist

What has the scientist claimed?

Speaking to the Human Genome Editing Summit at the University of Hong Kong, he said the girls had been "born normal and healthy" and they would be monitored over the next 18 years.

He said he had funded the experiment himself and confirmed his university, the Southern University of Science and Technology in Shenzhen, had not been aware of it.

Prof He also explained that eight couples - comprised of HIV-positive fathers and HIV-negative mothers - had signed up voluntarily for the experiment.

One couple dropped out, but there was "another potential pregnancy" of a gene-edited embryo in its early stages.

He said his study had been submitted to a scientific journal for review, though he did not name the journal. He was also evasive about other details, including the names of "some experts" who, he said, had reviewed his work and offered feedback.