Indian MP and former UN diplomat Shashi Tharoor has been charged with aiding his wife’s suicide in 2014.
Sunanda Pushkar's unexplained death was initially treated as suicide, but police later said she had been murdered, without naming a suspect.
Police in Delhi have now charged Mr Tharoor with abetment to suicide and cruelty to his spouse, reports BBC on Monday.
Mr Tharoor tweeted saying he intends to "vigorously" contest the "preposterous charges" against him.
Mr Tharoor, an MP with India's main opposition Congress party, married Ms Pushkar, a former Dubai-based businesswoman, in 2010. She was found dead in a five-star hotel in Delhi on 17 January 2014.
The cause of death is still unclear.
The first post-mortem report after her death suggested she may have died of a drug overdose - reports said Ms Pushkar had been on medication.
Subsequent reports since then spoke of "poisoning", "mysterious injection marks" and according to one report, a "deep bite" on her palm.
The couple became embroiled in controversy over a series of Twitter messages before Ms Pushkar's death that appeared to reveal Mr Tharoor was having an affair with a Pakistani journalist.
Ms Pushkar and Mr Tharoor later insisted they were happily married and blamed "unauthorised tweets" for causing confusion.
A career diplomat for 25 years, Mr Tharoor served as undersecretary general at the United Nations for communications and public information.
In 2007, he lost the election for the post of UN secretary-general to Ban Ki-moon, after which he announced his retirement from the United Nations.
He entered Indian politics in 2009, but was forced to resign from his first ministerial position in 2010 amid controversy over his involvement in bidding for a cricket team.
Ms Pushkar had allegedly received a free stake in the Indian Premier League franchise he was bidding for.
He was appointed minister of state for human resource development in 2012.