New Delhi/Thrissur: A friend of Sunanda Pushkar who dropped her to the hotel where she was later found dead has been quizzed in connection with her murder and 12 more people including her husband Shashi Tharoor will soon be questioned, Delhi Police said Friday even as Tharoor sought a professional probe in the case without any political pressure.

Sunil Trakru, a businessman and a close friend of Pushkar, has been questioned twice, a few days before the registration of the FIR Jan 4, a Delhi Police officer told IANS, adding Trakru's name had surfaced during the questioning of Tharoor's domestic help Shri Narayan Singh in November last year.

Singh, who was again questioned Thursday for a few hours, had revealed that the couple had a fight a day before Pushkar was found dead. He had also said that Trakru had dropped Pushkar from the Delhi airport to Hotel Leela Palace where she was found dead in her room (number 345) Jan 17.

The couple had returned from Kerala Jan 14 but Tharoor went to his house in Lodhi Colony, while Pushkar left for the hotel.

Delhi Police officials also told IANS that they will soon question 12 more people including Tharoor, Pushkar's son Shiv Menon, her two brothers Ashish Dass and Rajesh Pushkar and her cardiologist Rajat Mohan.

They are also looking for a person named 'Kaitie' whose name surfaced during arguments between Tharoor and Pushkar, overheard by Singh.

Police will also quiz Tharoor's personal assistant Rakesh Kumar Sharma, and another family friend Sanjay Dewan, who found Pushkar dead when he came to enquire about her health. At that time, Sharma was also present in the hotel.

Senior journalist Nalini Singh, with whom Pushkar was believed to be in touch over phone before her death, will also be called to join the probe, the officer added as well as Tharoor aides Shiv Kumar Prasad and Abhinav Kumar and driver Bajrangi.

The special team investigating the murder Friday visited the hotel where they questioned the staff and also went to the room where Pushkar had stayed.

Tharoor meanwhile sought a "professional" investigation into his wife's death without "political" pressure and a "pre-determined" mind.

"I have lost my wife and have not been allowed to mourn in peace," the former central minister told the media outside at a private ayurvedic centre in Thrissur where he has been undergoing a 14-day general wellness treatment since Dec 26.

"I was completely taken aback because none of us in the family had any reason to believe that there was foul play in her passing away," he said.

"It is very important that this (investigation) be done professionally without any pre-determined outcome or political pressure," he added.

Tharoor said he had been silent on the issue for a whole year in order to help police establish the facts of the case.

"I have pledged my full cooperation with police and there have been numerous reports that my silence is sinister.

"The reason (for my silence) would be obvious that when a police inquiry is going on, it is my duty not to undermine it in any way.

"I have been silent saying, let the police do the work," he said. "My interest as a bereaved husband is to the why and what happened and not to chase TRPs."

Tharoor said he was "troubled" by the conclusion of the investigation and the way it was carried out.

"There has been a lot of misinformation, distortion and outright lies that has been coming out. A fair enquiry has to be there on Sunanda's sad demise. I will not engage in public discussion and I have written to the Delhi Police yesterday (Thursday) that I would fully cooperate with them and would like answer all their questions at the earliest," said Tharoor and ignoring a volley of questions by the media, went back inside the ayurveda centre.