The ornaments comprised gold chains, rings and earrings.
Three persons from Surat in Gujarat were detained at Katni station in Madhya Pradesh after they were found to be carrying about 14 kg of gold ornaments valued at Rs 7 crore.
The trio were taken into custody by personnel from the Government Railway Police (GRP) after they got off the Tapti Ganga Express at the station.
The three men carried the ornaments in plastic cases inside a backpack.
R K Patel, in-charge of the GRP police station in Katni, said the men were moving suspiciously when they were stopped at the main gate of the station. "When we brought them to the station and checked their luggage, we found gold chains, rings, earrings and other items. The weight of the ornaments is around 14 kg with a market value of nearly Rs 7 crore. The three men have bills of about Rs 5.5 crore," Mr Patel said.
He added that the three men told them that they came from Surat in Gujarat.
The GRP also informed the officials from GST and Income Tax departments who have reached the station to question the trio and examine the bills with them.
Mr Patel said they would take further action depending on the findings of the probe.