A Japanese man at the centre of a surrogacy scandal in Thailand has submitted a DNA sample to local authorities, police said Tuesday.

The 24-year-old man had said he wanted to produce between 100 and 1,000 babies, according to the co-founder of an organization that provides surrogacy services in Thailand and other countries.

"The best thing I can do for the world is to leave many children," Mariam Kukunashvili of New Life Global Network quoted him as saying.

The DNA samples were submitted by the man's lawyer, according to a spokesman for the deputy police chief.

The man did not appear for a police summons on Monday, but so far he faces no official charges.

Thai police are investigating him for possible trafficking offences after it emerged that he had taken three babies out of the country in the past year, Police General Ek Ungsananont said.

Investigators said DNA tests confirmed that nine infants found in a Thai condominium two weeks ago shared a common father.

The apartment and the nannies were registered under the name of the Japanese man. Officials placed the infants in the care of social services.

Thailand has re-examined its surrogacy laws following a scandal in which a surrogate baby with Down syndrome was left behind by an Australian couple.

Authorities have been examining surrogacy clinics and practices around the country, but complain that legal loopholes make cases difficult to investigate.