The chargesheet was filed in the court of Metropolitan Magistrate Dharmender Singh here. On February 23, Tharoor said he was looking for a conclusion in his wife's death case.
Pushkar was found that night dead in room no 345 of Leela Palace, the five-star hotel in Delhi's Chanakyapuri.
"No one who knew Sunanda believes she would ever have committed suicide, let alone abetment on my part", he wrote on Twitter.
Tharoor and Pushkar married in late 2010, the third marriage for both of them.
The chargesheet says that the brothers and son of Pushkar made "no allegations against anyone".
Shashi Tharoor says he would contest the chargesheet in the Sunanda Pushkar death case. The AIIMS hospital confirmed that hers was an unnatural death.
The autopsy report revealed Pushkar died due to a radioactive poison.
Pushkar was found dead on the evening of January 17, 2014.
Subsequent reports since then spoke of "poisoning", "mysterious injection marks" and according to one report, a "deep bite" on her palm. He said in October 2017 the statement was made that nothing has been found in the investigation, it is really suspicious that in six months they concluded that there has been an abatement to suicide.
Police, however, maintained the charges against Tharoor were finalised on the basis of "medico-legal and forensic evidence", the newspaper said.
"The matter is now sub-judice, so we can not reveal contents of probe report", Deependra Pathak, Delhi Police Chief Public Relations Officer, said in Delhi. A murder case was registered against unknown people. Soon after, Delhi Police issued a statement justifying its action.
In April, the special investigation team (SIT), after conducting thorough professional and scientific investigations, had prepared a draft police report under section 173 of the Criminal Procedure Code.