Taslima Nasrin, who left India after protests broke out against her in West Bengal last year, landed in Delhi on Friday morning after spending more than four months in Sweden.
The 45-year-old Bangladeshi writer arrived at the Indira Gandhi International airport and was immediately taken away by security agencies to an undisclosed destination, CNN-IBN correspondent Sumon Chakravarti reported exclusively for bdnews24.com.
Taslim has a visa for India valid till August 12.
Taslima Nasreen threatened by radical Islamists became a victim of political ping-pong in India last November, bundled from one city to another in a controversy critics said had shamed the secular state.
Authorities rushed the controversial writer, who criticises the use of religion as an oppressive force, from her home in Kolkata after protests against her by Muslim groups led to riots, forcing the army to be called onto the streets.
The riots appeared to be the culmination of years of simmering anger at Taslima, by a section of radical Muslims, for saying Islam and other religions oppress women. Indian clerics had issued a "death warrant" against her in August.
After the riots, police moved her to the western state of Rajasthan and then Delhi under police protection. She eventually had to leave India for her own security.