New Delhi: Congress MP Shashi Tharoor's domestic help, Narayan Singh, interrogated by Delhi Police twice earlier, was Thursday called for questioning, police said.
The special team investigating the murder of Tharoor's wife Sunanda Pushkar took Singh to an undisclosed location in south Delhi, an official said.
On Wednesday night, Tharoor's staff received a notice from police asking Singh to join the probe.
"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.
Police Commissioner B.S. Bassi said they had not sent any legal notice to Tharoor to join the probe yet.
Tharoor, in a letter to Bassi dated Nov 12 that became public knowledge Wednesday, said a Delhi Police officer attempted to implicate him and Singh in the murder of his wife.
Tharoor said four Delhi Police officers interrogated Singh for 16 hours Nov 7 and for 14 hours Nov 8.
On both days, Tharoor alleged that Singh was "repeatedly physically assaulted by one of your officers".
Pushkar was found dead in mysterious circumstances in a luxury hotel here in January last year.
Police said Tuesday that Pushkar was poisoned to death.