Unknown coins found in Khalpara village of Mekhliganj subdivision (Coochbehar District, earlier Coochbehar state) today. As per source approximate 40-50kg coins found when one of villager digging soil near by his house. Khalpara village is under Uchalpukuri block.
In history of Kamta we know that Koch King Nara Narayana started Narayani coin during his reign started from 1534 AD. The script on this coins is neither Bengali nor Assamese. It is almost similar to that of Narayani coin. Narayani coin was the sign of sovereignty.
Narayani coins were prevailing in some other neighboring countries like Bhutan, Nepal Burma and obhiously present day Bangladesh. At that time the Narayani coin was the medium of trade in Khasi, Kachar, Jaintia, Manipur, Tripura with North East as well as some parts of south East Asia. From the wide spread expansion of Narayani coin, there was a great deal of trade and commerce in the state of Cooch Behar.
In 1866, the British government of India stopped the circulation of Narayani coin. However, later on, the Maharaja of Cooch Behar used to prepare coin as a commemorative coin for the first day of ascendency.
We can see the details of narayani coins in thesis “KOCH COINAGE: A STUDY INHISTORICAL PERSPECTIVE” – Dr. Debajit Dutta guided by Dr. Bijoy Kumar Sarkar of North Bengal University.