After the recent arrest of actress Rhea Chakraborty for allegedly buying cannabis for her late actor-boyfriend Sushant Singh Rajput, the names of at least 20 top Bollywood celebrities — from actors to filmmakers to designers — have surfaced in the drugs case that has captivated and polarised India in recent months.

Of them, four leading Bollywood actresses —  Rakul Preet Singh,  Deepika Padukone, Sara Ali Khan and Shraddha Kapoor — have been summoned by India's narcotics control authority for questioning this week after WhatsApp chats retrieved from Rhea's mobile phone indicated they used drugs.

"Rakul Preet, who was summoned on Thursday, has expressed her inability to turn up, as she is currently in Hyderabad. We will question her on Friday. However, leading celebrity designer Simone Khambatta was grilled by Narcotics Control Bureau sleuths at the Mumbai office in the morning," an official told UNB.

Deepika has also been asked to appear on Friday, while Sara and Shraddha will be questioned on Saturday, the official said, adding that Sushant Singh's talent agent Jaya Saha has already been grilled in the case.

The Narcotics Control Bureau, in fact, widened its probe into the Bollywood drugs scandal after WhatsApp chats retrieved from Rhea's mobile phone apparently revealed that a number of celebrities have been procuring banned substances like cannabis, weed and hash from dealers with links to foreign countries.

"We are probing the nexus between Bollywood celebrities and drug dealers who have been sourcing high-end banned substances from neighbouring countries through an organised network. The aim of the probe is to break the chain once and for all," the official said.

Also read: Sushant Singh Rajput death: CBI to interrogate Rhea Chakraborty

Meanwhile, Rhea's lawyer Satish Maneshinde has claimed that it is a "witch-hunt" by national agencies against his client and others. "I challenge the agencies to prove their case in a court rather than in front of the media. I will go after the TV channels that have tarnished my client's reputation," he told an Indian TV channel.

Rhea was arrested by the Narcotics Control Bureau on September 9, following days of questioning, in connection with the death of 34-year-old Sushant Singh, whose body was found hanging from a ceiling fan in his Mumbai flat on June 14.

Also read: Sushant Singh Rajput's death fuels debate on Bollywood nepotism