The woman was attacked last week after filing a police complaint in the city of Fatehpur in Uttar Pradesh, about 560 kilometers (350 miles) southeast of New Delhi, according to police officer Kapil Dev Mishra.
She was hospitalized with burns covering 99% of her body and died six days later, said Dr. Sanjay Kala, a surgeon who treated her.
Kala said a medical examination showed that rape was unlikely.
Mishra said the man accused by the woman is being held on charges of rape and attempted murder and a police investigation is ongoing.
It was the second burn attack of an alleged rape victim in Uttar Pradesh this month.
In the first attack, a 23-year-old woman was allegedly doused with gasoline and set ablaze by five men, including two she had accused of rape who were out on bail. She was on her way to court for a hearing in her case when she was attacked.
This week marked the seventh anniversary of a gang rape on a moving bus in New Delhi that triggered massive protests that pushed lawmakers to create fast-track courts dedicated to rape cases and stiffen penalties for those convicted of the crime.