They said a team of Directorate of Revenue Intelligence officials, acting on a tip-off, signalled the car to stop at a checkpost on the Tamil Nadu-Puducherry border and when it sped away, gave chase and intercepted at T R Pattinam in Karaikal.
Karaikal is an enclave of the Union Territory of Puducherry.
A search of the vehicle revealed the gold biscuits inside following which the two were arrested. On being questioned, the duo said they were taking the gold from Nagapattinam to Chennai.