The Narcotics Control Bureau (NCB) arrested one Regel Mahakal, who was absconding in a drugs case related to the death of actor Sushant Singh Rajput, in Mumbai on Wednesday.
Mahakal will be produced before a court later in the day.
"He used to supply drugs to (another accused) Anuj Keshwani who further supplied it to others," an official said.
He added the NCB was also conducting raids at Milat Nagar, Lokhandwala, from where a substantial quantity of drugs has been recovered so far.
The NCB had on September 12 conducted several searches in the case based on information provided by Keshwani who was arrested after one Kaizan Ebrahim disclosed his name. Ebrahim had said that Keshwani was his supplier for contrabands.
The NCB, which is probing the drug angle in Sushant's death case, started the investigation after it received official communication from the Enforcement Directorate (ED), in which there were various chats related to drug consumption, procurement, usage and transportation.
The ED had on July 31 registered a case information report in the actor's death case after a First Information Report was filed by his father K K Singh against Rhea Chakraborty in Bihar on July 28.
Rajput was found dead at his Mumbai residence on June 14.