Congress MP Shashi Tharoor has sent a legal notice to Union Law Minister Ravi Shankar Prasad seeking an "unconditional apology" for calling him a "murder accused".
Posting his legal notice on Twitter, Mr. Tharoor called the law minister's statement "false, malicious and defamatory".
"When India's Law Minister falsely invents a murder case against a political opponent, what hope for justice & democracy?" Mr. Tharoor wrote on Twitter.
The legal notice sent by law firm Suraj Krishna and Associates on behalf of Mr. Tharoor states that "you are well aware that in the ongoing criminal case against Shashi Tharoor in relation to the death of his late wife Sunanda Pushkar, the offence alleged by the prosecution against him is not that of murder and the trial court is yet to frame any charges against him.
"Even the police charge sheet against Shashi Tharoor does not contain any allegations of murder. Your purposeful comment that Shashi Tharoor is chargesheeted is a serious allegation of murder seems to have some oblique motives," the notice reads.
Accusing Mr. Prasad of defaming Mr. Tharoor, the notice said that "in the above circumstances, you have clearly committed the offence of defamation for which you are liable to be tried before a court of law".
"You are hereby called upon to tender an unconditional and written apology within 48 hours of the receipt of this notice for making such an untrue, false and baseless imputation against Shashi Tharoor... to avoid the consequences of a litigation," the notice said.
Moreover, the Congress leader has also demanded that videos of the law minister making these remarks must be taken down from social media.
Sunanda Pushkar was found dead in a suite of a luxury hotel in Delhi on the night of January 17, 2014.
Shashi Tharoor has been charged under Sections 498A (husband or his relative subjecting a woman to cruelty) and 306 (abetment of suicide) of the Indian Penal Code, 1860, but has not been arrested in the case.
Read the legal notice below.