His arrest came after another drugs peddler Kaizan Ebrahim revealed to the NCB that he procured drugs from Keshwani for onward supplies to other clients.
Following further revelations made by Keshwani and others, the NCB had swooped down on other drug dealers and peddlers in the city, and at total of around 16 have been rounded up so far.
In the latest round, the NCB nabbed seven others - Karanjeet Singh Anand, Dwayne Fernandes, Sanket Patel, Ankush Anreja, Sandeep Gupta and Aftab Fateh Ansari (all from Mumbai) and Chris Costa (from Goa).
These arrests are part of the case in which the NCB has earlier arrested Sushant's girlfriend and actor Rhea Chakraborty, her brother Showik, Sushant's house manager Samuel Miranda, the later actor's staffer Dipesh Sawant, and drug peddlers Abdul Basit and Zaid Vilatra.
Sushant was found dead at his Bandra home on June 14, triggering a huge upheaval in Bollywood and simultaneous probes by the NCB, the Enforcement Directorate and the Central Bureau of Investigation in various aspects of the case.