The passenger, hailing from Thrissur district, has been detained. He had arrived by the Qatar Airways flight at 3 am today.
A gold assayer, who examined the bars, found them to be of 24 carat purity, a customs press release said.
The Customs officials had seized 6.5 kgs gold in the last two days, including 1.4 kg from a consignment at the Air Cargo Complex, the release said.