The Narcotics Control Bureau (NCB), which is probing an alleged Bollywood-drugs nexus, on Wednesday summoned actors Deepika Padukone, Shraddha Kapoor, Sara Ali Khan and Rakul Preet Singh, among others, for questioning, an official said.

Padukone has been summoned on Friday, the senior NCB official said here.

The NCB, which began the probe after a drugs angle came to light in connection with actor Sushant Singh Rajput's alleged suicide, has now widened its investigation and asked these A-list celebrities of the Mumbai film industry to "join the probe", he said.

Earlier, NCB sources had claimed that there was a "reference" to Rakul Preet Singh and Sara Ali Khan in the statement of Rhea Chakraborty, who has been arrested in the case.

Deepika has been called to record her statement on September 25, Sara Ali Khan and Shraddha Kapoor on September 26 while Rakul Preet Singh, Rajput's talent manager Shruti Modi and designer Simone Khambata have been asked to appear on Thursday, September 24, the official said.

Jaya Saha, a talent manager who was questioned in the case, provided some important information, he said.

Earlier, Padukone's manager Karishma Prakash was summoned to join the investigation, but she sought time due to ill health, he said, adding she was exempted from appearance till Friday.

Prakash's WhatsApp chats included conversations about drugs with one `D', NCB sources said, adding that the agency wanted to find out who this person was.

The NCB has arrested actor Rhea Chakraborty, Rajput's girlfriend, for alleged procurement and use of drugs.

On Wednesday, film producer Madhu Mantena arrived at the NCB guest house here to record his statement.