Taking forward its probe into the murder of Sunanda Pushkar, the wife of Congress leader Shashi Tharoor, Delhi Police questioned their domestic help Shri Narayan Singh but said they had not yet called the MP for questioning.

Singh, who had been interrogated by police twice earlier, was Thursday again called for questioning, police said.

The special team investigating the murder of Pushkar took Singh to an undisclosed location in south Delhi, an official said.

Tharoor’s staff had Wednesday night received a call from police asking Singh to join the probe.

“Shri Narayan was in Himachal Pradesh. He came here today (Thursday) morning and left for the police station,” a staff member at Tharoor’s residence here told IANS.

Pushkar was found dead in her south Delhi hotel room Jan 17, 2014 in mysterious circumstances. Police registered a murder case earlier this month based on a final medical report by AIIMS which said she died due to poisoning.

Singh was present at the hotel when Pushkar died.

Police officials said that they are likely to call other members of Tharoor’s staff as also hotel staff for questioning in the next few days.

Police Commissioner B.S. Bassi told the media that Tharoor has so far not been asked to join the investigation.

“We have not served any formal legal notice to anyone. The investigation officer is yet to get more information and, only after that, he will decide which person is to be examined,” Bassi said.

“As of now, no notice has been given yet because there are many facets to investigate,” he added.

Tharoor, in a letter to Bassi dated Nov 13 that became public knowledge Wednesday, said a Delhi Police officer attempted to implicate him and Singh in the murder of his wife. However, Bassi denied the allegation.

Tharoor is undergoing ayurvedic rejuvenation treatment at a centre at Thrissur in Kerala.

Perumbayil Ayurveda Mana (ayurveda centre) owner Sajeev Kurup told IANS Thursday that Tharoor was busy finishing his book and he was undergoing a 14-day general wellness programme for ailments like frozen shoulder and stiffness.

“He was here for a week in September and then he was told to undergo a 14-day in-house therapy. His present 14-day therapy started Dec 26,” Kurup said.

Kurup added that the treatment of the Lok Sabha member from Thiruvananthapuram will be over by Friday and he should be out of the centre in the evening.

A day before her death, Pushkar and Tharoor issued a joint statement denying reports that they had a row over his alleged affair with a Pakistani journalist.

Tharoor was then a minister in the government of then prime minister Manmohan Singh. He was re-elected to the Lok Sabha in May last year.