Acting on a tip-off, Abul Ashan (41) was apprehended at Vizianagaram station near here last night while he was travelling in the Yeshwantpur-Howrah Express train, Government Railway Police DSP V Bhima Rao said.
During checking of his bags, five kg of the narcotic kept in 28 packets was seized.
The drug has been sent to the forensic science laboratory in Hyderabad for chemical analysis, Rao said.
The accused has been arrested and would be produced in the court today, police said, adding that search was on for his accomplice, who was at large.