Sub-Divisional Magistrate Alok Sharma has asked police to find out the cause of poisoning and also to specifically probe murder or suicide angle.
According to police sources, the post-mortem report submitted to the Sub-Divisional Magistrate on Monday said Pushkar died due to drug overdose.
There were more than a dozen injury marks on her person, suggesting a scuffle, it said.
Sharma, who got the report from All India Institute of Medical Sciences, had declined to reveal its contents saying it was sealed.
The post-mortem was conducted by a three-member team of doctors headed by Sudhir K Gupta.
Sunanda Pushkar was found dead under mysterious circumstances in her room at The Leela Palace hotel in Delhi Delhi on Friday.
Police investigators had recovered two strips of alprax drug from her hotel room.
"The huge quantity of consumption of such drug may affect functioning of brain and leads to a comatose situation," said a police officer.
Pushkar's death followed days of public spat involving her and a Pakistani woman journalist who Pushkar said was pursuing her husband. The journalist denied the charge.
At one time, Pushkar said she would divorce the minister. Later, she and Tharoor issued a statement saying they were happily married
Evidence of drug overdose in Sunanda's body
'Tharoor had no role in Sunanda's death, but can't say it's suicide yet'
Delhi police "highly compromised": Kejriwal
Sunanda Pushkar cremated
Sunanda case: Tharoor records statement before SDM