The filmmaker said he wanted to expose the drug use in the industry.
Filmmaker and journalist Indrajit Lankesh on Tuesday claimed that at least 15 people in the Kannada film industry were involved in drug trafficking.
He made the claim a day after deposing before the police to share the information about the alleged drug racket operating in the film industry.
"I have given (names of) around 15 people whom I know are into drug business. I shared those names with the police," Mr Lankesh told PTI.
Mr Lankesh was questioned for nearly five hours by the Central Crime Branch on Monday for his statement that there were many people in the film industry who were into the drug business either as consumers or sellers.
The filmmaker made the statement in the wake of the Narcotics Control Bureau busting a drug trafficking racket in Bengaluru and said some "prominent musicians and actors" in Karnataka were under its scanner.
The filmmaker said he wanted to expose the drug use in the industry.
"There are celebrities, when they start smoking and start doing cocaine, they are the brand ambassadors of youth today. These people think it is cool..," he added.
Mr Lankesh said he suspected that some of the parties organised in the "Sandalwood" were hosted by drug mafias within the industry.
Mr Lankesh did not rule out the possibility of the Mumbai underworld behind the supply of drugs to a section of people in the Kannada film industry.
Meanwhile, the police said they were probing the matter.