The prosecutor had said that NCB had found evidence from Sameer regarding some chats indicating that he was planning to mix CBD oil and other chemicals with marijuana.
Sameer Khan was arrested by Narcotics Control Bureau on January 13 in connection with a drug case.
A team of the NCB on Thursday conducted searches at Khan's residence in suburban Bandra. No seizure was made from his house, the official said.
In a post on Twitter, the NCP leader, without mentioning any incident, said the law will take its due course and justice will prevail.
Sameer Khan, Malik's son-in-law, was called for questioning at the NCB's Ballard Estate office in South Mumbai in the morning.