NEW DELHI: Four key people involved in the Sunanda Pushkar murder case investigation were questioned on Wednesday. While senior police officers refused to disclose details, sources in the special investigation team told TOI that among those questioned were the then personal security officer of Shashi Tharoor and two businessmen.

Sources also claimed that Tharoor's family friend Sanjay Dewan was questioned on Wednesday. He has been questioned twice earlier— once last January by the SDM looking after the inquest in Sunanda's death and the second time in November when police were probing loose ends in the case.

A source also said that SIT would question one of Tharoor's staffers, Rakesh Sharma, yet again in coming days as he has emerged as the man who had bought the Alprax for Sunanda and SIT has found contradictions in his statement.

Police did not disclose the identity of the two businessmen but sources said they were staying at Leela Hotel since November 2013. "During interrogation, it was found that the men had not given proper documents and some other person had submitted his identity proof on their behalf. We are probing why this happened and why the men were staying from three months before January 17. They were also quizzed about the purpose of their stay," a source said.

The four men were questioned on Thursday by a team comprising additional DCP Kushwah, ACP Safdarjung Somendra Pal and STF chief inspector Rajender Singh. The DCP has been asked to be the custodian of files to maintain secrecy. They were later taken to the anti-auto theft squad's office in Vasant Vihar where the SIT has been headquartered.

Sanjay Dewan was questioned about the interactions which took place in suite number 345 of Leela hotel on January 17 evening and why Sunanda was not taken to the hospital immediately. The PSO was questioned about his whereabouts on January 17 and his interaction with Tharoor.

Also on Wednesday, sources said the woman known as Katy—over whom the couple fought often—was one Katherine Abraham. Police, however, did not elaborate on who she was. A source said she was a common friend of the Tharoors.