The Central Bureau of Investigation (CBI), probing the case of the death of Bollywood actor Sushant Singh Rajput, is seeking legal opinion on a new FIR filed by the late actor's girlfriend Rhea Chakraborty against his two sisters and a Delhi doctor.

The FIR was registered by Rhea at the Bandra police station here against Priyanka Singh and Mitu Singh as well as Ram Manohar Lohia Hospital doctor Tarun Kumar for allegedly issuing a bogus prescription for Sushant to help him with his anxiety issues.

A CBI source said that the agency will soon take a decision on the issue, even though there was no official confirmation from CBI officials.

The source said that the CBI is taking legal opinion as the Supreme Court had on August 19 approved to hand over the Patna Police FIR to the central agency as directed by the Centre.

The CBI SIT has already questioned a number of accused including Rhea, her brother Showik, father Indrajit, Sushant's ex-manager Shruti Modi, Sushant's house manager Samuel Miranda, flatmate Siddharth Pithani, house staff Dipesh Swant, Neeraj Singh and Keshav Bachne and several others in the case.

Rhea, Showik, Miranda and Swant have been arrested by the NCB in connection with the drugs case related to the death of Sushant.

The NCB registered the case on the request of the Enforcement Directorate (ED) after several chat details showed a drugs angle. The death of Sushant is being investigated by the CBI, ED and the NCB.