DNA tests have proven that nine babies found in a Bangkok condominium last week have the same father, but authorities have yet to prove he is the Japanese businessman at the center of the case, senior police doctor Jongjate Aojanepong said on Tuesday.
He told a news conference that according to birth certificates found by investigators, the businessman has been named as the father of 15 babies.
Nine of the 15 are now under guardianship at a government nursing home. Four children were discovered by immigration officials leaving Thailand for Cambodia. And a set of twins is receiving treatment at a hospital in Bangkok.
Police plan to test the DNA of the twins when they recover from an unspecified illness.
The police physician said it appeared the children were conceived from eggs from "various races" of women.
The doctor said it has not been determined if the children were part of a human-trafficking scheme.
Deputy National Police Chief Ake Angsananon said officials have questioned seven people, including nannies, surrogate mothers and a lawyer, about the discovery. No charges have been filed against anyone.
"The most important thing is to provide safety to 15 babies, which number may increase in the future. The second most important matter is to apply existing legal measures in a bid to prevent misconduct in the future," Ake said.
He added that Thai police are seeking help from Japanese, Cambodian and Indian authorities in their investigation.