The Delhi police on Monday charged Congress MP Shashi Tharoor with abetting the suicide of his wife Sunanda Pushkar more than four years after she was found dead in a hotel room in south Delhi.

An officer confirmed to HT that police mentioned an overdose of Alprax tablets as the cause of Pushkar’s death. The special investigation team also charged Tharoor under Section 498A (cruelty to wife) of the Indian Penal Code (IPC) in their charge sheet submitted to a city court on Monday. For the past three and a half years, police were probing the case as one of murder after filing an investigation report under Section 302 (murder) against “unknown” suspects. The charge sheet reportedly mentions details of the couple’s strained relationship and allegations of Tharoor’s extra-martial affair as a reason why Pushkar was depressed and overdosed on Alprax tablets.

The 51-year-old had not left behind a suicide note.

The court is yet to take cognisance of the charge sheet and has fixed May 24 as the next date of hearing. Pushkar was found dead in her suite at the Leela Hotel on the evening of January 14, 2014.

Delhi police chief spokesperson Depender Pathak said they charged Tharoor with abetting suicide and cruelty after analysing the medico-legal and forensic evidence in the case. He said the investigation team also took the opinion of “psychological autopsy experts” before reaching this conclusion.

A police officer, who did not wish to be named, said they charged Tharoor with abetment to suicide on the basis of medical reports such as injury marks on Pushkar’s body. As evidence of cruelty leading Pushkar to commit suicide, police have reportedly attached a statement of Tharoor’s help Narayan Singh who has claimed to have seen the couple fighting. Singh has also reportedly claimed he was an eyewitness to one such fight, which was violent.

Police used the psychological analysis reports of five people, including Tharoor and his domestic help, to establish the couple’s strained relationship.

Police have attached medical reports about the bruises on Pushkar’s face and wrist, which they suspect had been caused during a scuffle. The charge sheet, which runs into 3,000 pages has statements of hotel employees, Naryana Singh, and also Pakistan-based journalist Mehr Tarar. Police have attached Tarar’s messages with Tharoor as evidence, which they suspect led to the couple’s strained relationship.

A day before her death, Pushkar and Tarar had a public spat on Twitter with the former accusing Tarar of having an affair with Tharoor. In all these years, Tarar has claimed that her name was dragged into the case for no reason and that she was in Lahore at the time of Pushkar’s death.

Tharoor took to Twitter and called the charge sheet “preposterous”. In a series of tweets, he said, “I have taken note of the filing of this preposterous charge sheet &intend to contest it vigorously. No one who knew Sunanda believes she would ever have committed suicide, let alone abetment on my part. If this is conclusion arrived at after 4+ yrs of investigation it does not speak well of the methods or motivations of the Delhi Police. In Oct 17, the Law Officer made a statement in the DelhiHighCourt that they have not found anything against anyone & now in 6 months they say that I have abetted a suicide. unbelievable!”

The Congress leader also said he will “stay off” Twitter for some time.

The Congress also backed Tharoor after the charge sheet was filed. “There can be no more falsehood in this charge except that a conspiratorial BJP leadership, including the Prime Minister, and I say that with a sense of responsibility, and the Delhi Police are seeking revenge on Tharoor. But Congress leaders, including Tharoor, will neither cow down nor bow down, we have full faith in the justice system which will once again prove the blind conspiracy of Delhi Police at the active instance of the revenge seeking factory of the Modi government,” said the Congress’s chief spokesperson Randeep Singh Surjewala.