The North Korean diplomat was held at the Hazrat Shahjalal International Airport with 27kg gold after he landed here last night, police said.
Customs and police officials said commercial councillor of North Korean Embassy Yung Num was tracked down as he arrived on a Singapore Airlines flight carrying the gold in his handbag.
19 kg of the gold was in the form of bars and rest in ornaments.
"We stopped him on a secret tip off as he tried to go out of the airport through the green channel...We have seized the gold," Joint Commissioner of Customs Kazi Mohammad Zia Uddin told reporters.
Airport police said they detained the diplomat and conveyed the matter to Bangladesh's foreign ministry for subsequent actions at the diplomatic level.