The Narcotics Control Bureau on Saturday arrested Dipesh Sawant, a member of Sushant Singh Rajput's personal staff, in connection with a drugs probe linked to the actor's death, officials said.
With this, the total number of people arrested in this case has risen to six.
The officials said Dipesh Sawant, who was being questioned since morning, has been arrested under sections of the Narcotic Drugs and Psychotropic Substances Act.
A senior NCB officer had earlier said that Sawant's role was that of a "witness" in the case, they said.
The federal anti-narcotics agency had on Friday arrested Showik Chakraborty, 24, the brother of main accused in this case Rhea Chakraborty, and Samuel Miranda, Rajput's house manager.
Various angles surrounding the death of the 34-year-old actor are being probed by three federal agencies, including the Enforcement Directorate and the Central Bureau of Investigation.
The agency is probing the drug angle in this case under criminal sections of the NDPS Act after the ED shared with it a report following the cloning of two mobile phones of Rhea.
The NCB has said it is looking into "the drug citadel in Mumbai, and especially Bollywood" in this case.
Rajput was found dead at his flat in suburban Bandra area on June 14.
