New Delhi: The Special Investigating Team (SIT) of Delhi Police probing the death of Sunanda Pushkar, wife of Congress MP Shashi Tharoor, has interrogated his domestic help Narayan Singh.

According to reports, Narayan has revealed that both Sunanda and Shashi Tharoor were uncomfortable with each other for months, before her death. Sunanda was upset with Tharoor's conduct and behaviour as the two fought on many personal and financial matters.

Narayan was interrogated at an undisclosed location in South Delhi for nearly five hours. The police has questioned him at least twice earlier. Singh, who was in Himachal Pradesh, arrived in Delhi on Thursday morning after investigators asked to join the probe.

Read: Sunanda Pushkar murder: SIT quizzes Shashi Tharoor's domestic help

Tharoor is reportedly in Kerala, at an ayurvedic clinic undergoing treatment. He is likely to be discharged on Friday.

Sunanda, who married Tharoor in 2010, had checked into The Leela Hotel in Chanakyapuri two days before her death on January 17, 2014. Tharoor's aides said the couple had checked into the luxury hotel because of renovation work at his Delhi bungalow.

It is also learnt that Narayan told the cops that he was with Pushkar at the hotel on January 17 when she asked him to rest at the official residence of Tharoor, then union minister and bring back a white outfit that she planned to wear for a press conference.

Read: Sunanda Pushkar murder case: Delhi Police issues notice to Shashi Tharoor

The name of a family friend Sunil has also surfaced in the probe. As reported, Sunil was the person who had picked Sunanda from the airport and taken her to Taj Palace hotel. Police are yet to interrogate Sunil.

Prior to her death, Sunanda was embroiled in a spat with Pakistan-based journalist, Mehr Tarar, whom she accused of stalking her husband Shashi Tharoor.

Delhi Police Commissioner B.S. Bassi on Friday said that as every aspect of the Sunanda Pushkar death case is being looked into, the outfit's PRO will provide an update to the media this evening.

"Every aspect is being looked into. I will ask the PRO to give you an update at 5 pm in evening if anything relevant comes up. But for time being, we can say whatever was told to you earlier, as far as I am concerned, the situation is same," Bassi said.

"Many things will happen, and at times, you may not be getting precise information. So, better wait for some time. As and when we get something relevant, we will share it with you. I would like to give you an update after three or four days," he added.

Read: Medical report rules out natural causes, says FIR in Sunanda Pushkar case

Bassi had earlier on Wednesday said that a Special Investigation Team (SIT) has been formed to carry forward the probe in the case.

Bassi also said that the police is as of now is proceeding according to the action plan, and added that every aspect is being examined carefully.