The Directorate of Revenue Intelligence's (DRI) Mumbai unit has seized a consignment of 25 kg heroin concealed in a consignment of groundnut oil at the Nhava Port Trust in Navi Mumbai, and arrested one person, officials said on Friday.

Following a tipoff, the DRI sleuths swooped on the port on October 4 and detected the huge narcotics contraband, valued at Rs 125 crore, among boxes of a cooking oil container arriving from Iran and are now probing the possibility of a bigger drug smuggling racket with international ramifications for India and other countries.