The 58 kg of gold, which has been seized, was allegedly smuggled via Moreh border in Manipur, official sources said.
The officials of Directorate of Revenue Intelligence (DRI) arrested these 12 carriers, including one woman, of Mizo and Manipuri origin from a guest house in Chittaranjan Avenue area. They were to hand over the gold to some local contacts, they said.
All of them had smuggled gold after concealing it under the clothes worn by them and inside certain machine items like compressor carried by them, the sources said.
The value of the seized gold is assessed to be Rs 18.33 crore, the sources said.
It is one of the biggest haul of gold so far this year. The DRI officials had in March last year seized 87 kg of gold from Kolkata.
The gold is of high quality and has Myanmarese marking on it. Efforts are on to ascertain people who helped them cross the border and others involved in it, the sources said.