The constables, attached to the Naya Nagar police station under Bhayander division intercepted some persons including the woman during night patrolling in Bhayander on November 20. On searching, the woman was found in possession of the demonetised currency worth Rs 20 lakh, they said.
Instead of reporting the matter to their higher-ups or the Income Tax department, the three policemen allegedly took away Rs 8.50 lakh from the woman, police said.
Following a complaint by the woman, the Naya Nagar police on Saturday registered an offence against the three personnel under IPC sections 392 (robbery) and 34 (acts done by several persons in furtherance of common intention), police said.
No arrest has been made so far in this connection, police said adding that further probe is on.