Police said they seized 30,000 tablets of the drug late last night and arrested Zasanga of Mizoram-Myanmar border Champhai town.
The Special Narcotic Cell officials again seized 43 grams of heroin this afternoon at Zemabawk near Aizawl.
The contraband was seized from Dalmunga (40) of Tiddim in Myanmar when he was trying to sell it to a woman, Police said.
The two accused, who allegedly smuggled the contraband from Myanmar, were booked under various sections of the Narcotic Drugs and Psychotropic Substances Act, 1985.