Rohan Adukia, the son of businessman Rakesh Adukia, was detained at Tribhuvan International Airport.
Adukia was apprehended at the airport upon his arrival in Kathmandu from New Delhi.
He was arrested and turned over to the Revenue Investigation Department by the Immigration Department.
Earlier, the Revenue Investigation Department searched the house of businessman Adukia as part of its inquiry into the smuggling of one quintal of gold from Tribhuvan International Airport.
Adukia's arrest brings the total number of people arrested in the case to 21.
He said that because he was banned by the Immigration Department at the Nepali port, he was detained and transported to the department along with his passport.
Rakesh has been absconding since his name was linked to the gold smuggling case.