Thrissur (Kerala), Jan 9 (IANS): Congress MP Shashi Tharoor Friday sought a "professional" investigation into his wife Sunanda Pushkar'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.

"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.

Pushkar was found dead in a Delhi hotel room Jan 17, 2014 in mysterious circumstances. Police registered a murder case earlier this month based on a medical report by AIIMS which said was poisoned.

Police Thursday questioned Tharoors' domestic help Narayan Singh.

Tharoor said he had been silent on the issue for a whole year in order to help police e1stablish the facts of the case.

"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.