Customs sources said they seized the tortoises last night from the baggage of one Ahamed Sirajudeen following specific information.
The passenger was about to board a Sri Lankan Airlines flight to Colombo enroute to Kuala Lumpur.
Investigations revealed that a person in Chennai is believed to have arranged for the illegal export of the tortoises through Sirajudeen, the sources said.
The seized tortoises and the passenger would be handed over to the Forest Department officials, they said.
Star tortoises are protected under Wildlife Protection Act, which banned their possession and transfer in any form, they said.
It was also protected under the Convention on International Trade in Endangered Species.