A man has been arrested at an airport in Sri Lanka for allegedly trying to smuggle gold bars hidden in his rectum.

Customs officers at Bandaranaike International Airport noticed that the man, 42, was walking with an odd gait, and conducted a search, reported the BBC.

Four gold slabs weighing a total of 400g and valued at about 2 million Sri Lankan rupees (S$19,600) were found inside the suspect's rectal cavity.

According to Sri Lankan newspaper The Nation, the suspect had arrived from Singapore.

Sri Lankan Customs spokesman Leslie Gamini told the BBC the man had been "finding it hard to walk".

He claimed that he worked for Sri Lanka's Ministry of Post, Postal Services and Muslim Religious Affairs after being taken into custody.

More than 70 people have been arrested this year for attempting to smuggle gold into Sri Lanka, the BBC said.

The smugglers usually buy the precious metal in cities such as Dubai and Singapore, where it is cheaper and there are fewer trade restrictions, and sell them in India, where import duty for gold is 10 per cent for a 100g bar.

India is the world's largest gold consumer, with a total consumption of 642 tonnes in the first nine months this year.

The country has been trying to control gold imports since 2013 to tackle a widening trade deficit. But smugglers have tried to get around the restriction by using human mules to swallow nuggets or hiding gold bars in dead cows.