The role of Rhea's brother Showik and his purported links with the people nabbed by the NCB are under the scanner of the agency and he and Rajput's manager Samuel Miranda are expected to be summoned for questioning soon, the officials said.
The official said the NCB might also summon actors Rakul Preet Singh and Sara Ali Khan, and designer Simone Khambatta this week.
The officials said Dipesh Sawant, who was being questioned since morning, has been arrested under sections of the Narcotic Drugs and Psychotropic Substances Act.
After Lakshmi Manchu and Taapsee Pannu, Rhea Chakraborty has found support in yet another colleague from the film industry.
The family lawyer said he was getting "frustrated" by the delay in the CBI taking a decision in the case.
Dominic Xavier wonders what the end game in the NCB's starstruck probe will be.
Both Singh and her husband are accused of consuming ganja
"I have nothing to do with drugs. I have prescription for the medicine which was found at my residence and the prescription has been handed over to NCB officials," Rampal told reporters.
Officials said Gaurav Arya, who runs a hotel in the coastal state, has been asked to depose before the central probe agency at its office in the Ballard Estate area of Mumbai on August 31.
The submission by the actress in a 12-page affidavit in which she said the "constant sensationalisation" was causing extreme trauma and infringement of privacy of her rights came a day ahead of the next hearing of her plea for transfer of the Bihar police FIR against her from Patna to Mumbai.
The NCB searched Singh's house and office in the morning as part of its probe into alleged drug use in the Hindi film industry.
Chakraborty, who appeared before the CBI for the first time, left the Defence Research and Development Organisation guest house complex in Santacruz a little after 9 pm, said an official.
'She came yesterday, she came today... we talked to her all day, questioned her. So, I cannot say she is not cooperating. She will come tomorrow too. 'So we are getting her cooperation,' NCB deputy director general (DDG) (south-west region) Mutha Ashok Jain told reporters after the questioning session.
NCB Deputy Director General (south-west region) Mutha Ashok Jain told reporters outside the agency's office later that Rhea will be called again on Monday for questioning and recording of her statement like Sunday.
Electronic gadgets were seized during the search at the house of the 47-year-old actor in suburban Bandra, said the central agency official. Summons was also issued to Rampal, asking him to appear before the drug law enforcement agency on November 11, he said.
The NCB has arrested a Goa-based man who allegedly had links with the accused in a drugs case related to actor Sushant Singh Rajput's death, an NCB official said on Monday.
Her brother Showik Chakraborty was also called by the CBI for the fourth day in a row for questioning in the case, the official said.
Several Bollywood personalities including Taapsee Pannu, Swara Bhasker and Anubhav Sinha criticised the media's mobbing of Rhea Chakraborty.
Agency sleuths claimed he was arrested after they obtained some "vital leads" into the narcotics case registered against Rajput's live-partner Rhea Chakraborty and others.
Commenting on the Narcotics Control Bureau investigation of a drug case, related to actor Sushant Singh Rajput's death case, Raut said, "The probe of the case started about murder and suicide. Now, narcotics came into the case. Nobody knows where will it go. It is under NCB's jurisdiction to summon anyone to join the probe."
SRK's persona and brand power has been built over nearly 30 years of public acclaim and love. Brands perhaps believe that his troubles are transitory and that as a human brand he has long legs capable of striding over controversies, explains ad guru Sandeep Goyal.
There was heavy police deployment outside the NCB office, where barricades were put up.
In her complaint sent to the Bandra police in Mumbai on Sunday, Chakraborty sought that Priyanka Singh and Dr Tarun Kumar, working with Ram Manohar Lohia Hospital in Delhi, be booked under relevant sections of the Indian Penal Code for forgery, the Narcotics Drugs and Psychotropic Substances (NDPS) Act and the Telemedicine Practice Guidelines.
'It breaks my heart to see her almost being lynched and burnt at the stake like a witch. 'How desensitised have we become?' 'We don't even want the truth to unfold.'
In her bail application filed in the HC on Tuesday, Chakraborty said she is just 28 years of age, and besides the probe by the NCB, she has been subjected to three more investigations by police and central agencies, and a "simultaneous media trial".
The agency acted swiftly on a reference from the government in Bihar, the home state of 34-year-old Rajput, where his family had lodged an FIR against Chakraborty.
'Yes, I said 'Sorry babu'. When you see a dead person, what else will you say?' 'I said sorry as he was no more. When you love someone and they die, you say sorry.' 'Sorry that you aren't here. Sorry that a joke has been made out of your death.'