Son Young-nam, first secretary at the North Korean embassy in Dhaka, landed in the city on a flight from Singapore on Thursday night.
His baggage was searched and almost 27kg (59lb) of gold bars and ornaments were recovered.
Authorities in Bangladesh say they plan to pursue charges against him.
Mr Son initially refused to allow customs officers and police to examine his luggage.
"He insisted that his bags cannot be scanned because he's carrying a red passport and he enjoys diplomatic immunity," Moinul Khan, head of Bangladesh's customs intelligence department told AFP .... http://www.bbc.com
