Customs officials caught a man at the international airport with 10 turtles in his underwear, which he was trying to smuggle into the city from Bangkok.
Faizan Khan, who had concealed the turtles, arrived by a Thai Airways flight on Thursday night along with two accomplices, Sheikh Nadir Ahmed and Sheikh Naushad Musa; all three are Indian nationals.
The Air Intelligence Unit of Mumbai Customs also seized six Persian cats, three Tarantula spiders (known to be extremely poisonous), 11 eggs of unknown birds, and pigeon and fish foods from the trio's bags.
PM Saleem, commissioner of customs, airport, confirmed the incident.
Sources said officials were keeping a close watch as they had prior information that the trio would attempt to smuggle these protected species into the country.
"We kept a watch on the three as they arrived and the moment they crossed the green channel without declaring anything, they were detained," said a customs official, requesting anonymity.
Only those passengers who don't have anything to declare are allowed to walk through the green channel.
Officials frisked the trio and found that Khan was wearing two underwears between which he had concealed 10 turtles. They also found that all three were carrying two Persian cats each illegally.
"Two cats are allowed per passenger provided the documentation is in order, but the three passengers did not have any documents," the official said.
Following the seizure, customs officials called wildlife authorities to clarify whether these species could be imported.
"After the wildlife authorities confirmed that these species are protected under the
Wildlife Protection Act, we fined the passengers and sent them back to Bangkok with the species and the eggs they were trying to smuggle in," the official said.
The trio was fined Rs 1.85 lakh and sent back on Friday.