The accused, identified as Subhash Sharma (23), was caught during a routine check on the Indo-Nepal border last evening, the Commandant of SSB, Shiv Dayal said.
Sharma was then handed over to the local police, they said.
During interrogation, he admitted that he had brought the smack from India and also disclosed his links with drug smugglers here, Dayal added.
A case under various sections of the Narcotic Drugs and Psychotropic Substance Act has been registered against the accused at Sonauli police station, he added.