The Council on Human Reproductive Technology said subsequent tests verified the identities of all but one of nine embryos, while police have been alerted over potential foul play.
Speaking to reporters on Tuesday night, the council’s chairperson, Raymond Liang, described the incident as “very serious”.
The blunder, which occurred in May, involved Heal Fertility, one of 19 clinics licensed to provide assisted reproductive services in Hong Kong.
The clinic had delivered two batches of embryo samples to the Chinese University for pre-implantation genetic testing.
Professor William Yeung, who sits on the council’s inspection committee, said six of seven embryo samples from the first batch did not match the DNA of their stated parents, while both of the samples in the other batch were also incompatible.
Laboratory staff have since verified the identities of eight embryo samples using past patient data, but one remained unaccounted for.
A second round of testing was then conducted on the embryos involved, and confirmed none were contaminated.
Yeung said the council was notified by the clinic in June. The council has since met doctors and specialists at the clinic, and has not discovered procedural errors or abnormalities in patients’ records.
“Now there are two centres involved. One is Heal Fertility; the other is Chinese University. We first need to find out the source of the error… and that requires some time,” he said.
The Department of Health said it was never notified by the clinic of the incident, constituting a breach of its code of practice which stated that any serious untoward event must be reported within 24 hours.
Joanna Leung, the head of the department’s Office for Regulation of Private Healthcare Facilities, said the clinic has been ordered to stop accepting new customers and notify affected ones.
It must also submit an investigation report within four weeks and propose rectification measures.