"I do not know the exact number this doctor has performed but it's in the hundreds," said Boonrueng Trireungworawat, permanent secretary of the Ministry of Public Health.
The doctor was not named.
Australian couple David Farnell and his wife Wendy made international headlines after a Thai woman they paid to bear their babies accused them of returning to Australia with the healthy baby girl while abandoning her twin brother Gammy, who has Down's syndrome and other health problems.
Most of the cases involving illegal surrogacies in Thailand have stemmed from one clinic in central Bangkok, Boonreung said.
DPA