CUSTOMS authorities in India have arrested a man who was attempting to board a flight in New Delhi with an endangered monkey in his underwear.

The suspect from the United Arab Emirates, who was detained along with two other travellers, had arrived from the Thai capital Bangkok and was about to take a connecting flight to Dubai on Jet Airways.

"Security personnel found the monkey in his underwear while frisking the transit passengers," a customs official said.

The 17-centimetre loris is a type of monkey native to India and southeast Asia, and is seen by some as possessing aphrodisiac qualities.

Petite and round-eyed with a white stripe down its face, "the monkey is an endangered species," said the official.

Another was discovered in a dustbin at the Indira Gandhi International airport. It had been abandoned because the men could not carry him.

Both monkeys have been handed over to animal welfare organisation People for Animals headed by former environment minister Maneka Gandhi, the official said.

The men, named as Hamad Al-Dhaheri, Mohammed Al-Shamsi and Rashid Al-Shamsi, were handed over to the Wildlife and Customs Department for further questioning and were later arrested by the police.

Authorities were trying to determine the exact origin of the monkeys.

Customs officials recently caught an Indian man at Mumbai's main airport with 10 turtles in his underwear, which he was trying to smuggle into the city from Bangkok, the Hindustan Times reported last week.

They also seized six Persian cats, three poisonous tarantula spiders and 11 birds eggs from the man and his two accomplices, the report said.

The newspaper quoted a customs official saying the men were fined and sent back to Bangkok with the protected species and eggs they were trying to smuggle.