[8] As Police Commissioner of Thane, he busted the fake international call centre racket at Mira Road[10] in which 6,500 US nationals were cheated.

He handled the cases of the TRP scam, the Anvay Naik suicide and the death of Sushant Singh Rajput.

[8][13] On 18 March 2021, the Maharashtra government removed Singh as commissioner in the aftermath of a security incident in which a parked car containing sticks of gelignite was discovered outside of the home of businessman Mukesh Ambani.

[14] On March 20, 2021 Singh in an eight-page letter to Chief Minister Uddhav Thackeray alleged that then Home Minister Anil Deshmukh had asked then Assistant Police Inspector Sachin Waze "to collect ₹100 Crore every month from businesses based in Mumbai".

[16] On 28 October 2021, a court in Maharashtra's Thane issued a non-bailable warrant against Singh in connection with a case of extortion.