The six birds survived the journey but had to be put down in the UK
Six live pigeons were found in a passenger's hand luggage by officials at Manchester Airport.
The man, who had travelled from Pakistan, was stopped by UK Border Agency officers on Friday.
Officers searched his bags and found five birds hidden in a wooden box and one in a plastic bag.
The birds had to be put down because of their risk to public health. Officials are considering if any action should be taken against the passenger.
Although pigeons are not listed under the Convention on International Trade in Endangered Species (CITES), the importation of live animals within hand luggage is illegal.
A spokesman for the UK Border Agency said: "The UK Border Agency is determined to crack down on the illegal trade in goods, and officers across the country are working to stop all types of smuggling, including live animals.
"Unfortunately, smuggling live animals in hand and hold baggage has become more common, with many cases being discovered across Europe, including the UK.
"This isn't the first time that passengers have tried to conceal live birds. We have also seen them strapped to people's bodies in the past."