In a surprise move, the probe into Sunanda Pushkar's mysterious death was transferred back to the South district police from the crime branch, two days after it was moved to the latter.
Top sources said on Sunday that the case was moved to south district police to ensure continuity in the investigation.
Senior police officials, however, did not respond to question as to why the case was first handed over to the crime branch if the Delhi police wanted to ensure continuity in the probe.
The probe into the high-profile case was transferred to the crime branch on Thursday considering its "sensitive nature" and "complexities" involved.
Earlier in the day, Sunanda's brother Rajesh came out in strong defence of Union Minister Shashi Tharoor, saying it was "unimaginable" that he could harm Sunanda and sought an end to the rumours that were hurting the family.
In a statement, Rajesh said Sunanda was one of the strongest personalities and to even remotely think that she would do any bodily harm to herself is "preposterous" and "should not be believed".
He also sought speedy investigation into the case "to put an end to the rumours that are hurting" the family.
On Tuesday, a sub-divisional magistrate had directed the Delhi police to investigate the murder or suicide angle in the case.
Sunanda, 52, was found dead in a five-star hotel in South Delhi on last Friday, a day after her twitter spat with Pakistani journalist Mehr Tarar over an alleged affair with Tharoor.
In a report to the police, sub divisional magistrate, who has recorded the statements of Sunanda's brother, son, Tharoor and his staff, had said that no family member suspected any foul play in the death.
The autopsy report had mentioned more than a dozen injury marks on Sunanda's body besides a "deep teeth bite" on the edge of her left palm.
The SDM in his report had concluded that Sunanda died if poisoning.
Image: Sunanda Pushkar, who was married to MoS Human Resource Development Shashi Tharoor, was found dead in a five-star hotel in New Delhi last Friday