The jeweller was on his way to Ratlam from Rajkot and was not carrying valid documents to prove authenticity of the gold jewellery, police said.
The seizure which is worth Rs 1.39 crore is significant in view of Lok Sabha polls to be held on April 24 in Ratlam under the third and final phase in Madhya Pradesh.
Identified as Dinesh Dhanjibhai Soni, the jeweller has not produced valid papers so far to prove that the consignment was genuine, due to which he has been detained by the police and a case registered, they said.