Mumbai, Aug 27 : Continuing with the high-profile probe into Bollywood actor Sushant Singh Rajput's death, the Central Bureau of Investigation on Thursday summoned brother of actress Rhea Chakraborty, Showik, for a grilling session, official sources said. Showik Chakraborty's questioning has been taking place at the DRDO and IAF guesthouse here since morning. Among other things, Showik is being confronted with the statements of Sushant's flatmate Siddharth Pithani, his house-help Dipesh Sawant, cook Neeraj Singh; and the CBI will also record his version in the matter. Showik was a regular visitor to the Mont Blanc duplex flat in Bandra where Sushant and Rhea lived and had also accompanied them on some foreign trips. As per Rhea's latest revelations, all three were equal partners in a new business venture -- Rhealityx Pvt. Ltd., considered a dream project of the late actor who was found dead in his home on June 14. Previously, Rhea, Showik and their father, retired Lt. Col. Dr. Indrajit Chakraborty, were subjected to grilling by the Enforcement Directorate (ED). In a latest development, the late actor's father, K.K. Singh made a sensational allegation on Thursday, accusing Rhea of 'murder', who he claimed has been poisoning his son Sushant for a very long time and demanded that the investigating agencies must arrest her and her associates. /IANS