Exiled Bangladeshi author Taslima Nasreen has said that she intends to leave India because her health is failing after living in hiding.
Ms Nasreen faced death threats in Bangladesh
The author has not been allowed to see any visitors for nearly four months.
Protests by Muslim groups in November forced the Indian authorities to move the controversial writer from home in Calcutta to a safe house in Delhi.
Ms Nasreen fled Bangladesh to Europe in 1994 after death threats. She lived in Calcutta for three years.
A Bangladeshi court said that she had "deliberately and maliciously" hurt Muslim religious feelings with her Bengali-language novel "Lajja", or Shame, which argued that the Hindu minority in Bangladesh was poorly treated.
Last year some Muslim groups say parts of her book Dwikhondito (Split into two) were derogatory to Islam.
Critics have accused the writer of calling for the Koran to be changed to give women greater rights, something she denies.
In an e-mail sent to her supporters, Ms Nasreen said that her confinement in Delhi was like living in "a chamber of death".
Protests against the author turned violent in Calcutta
"I am suffering from very high blood pressure... and have developed heart disease," she wrote.
"The blood pressure if uncontrolled can destroy my heart, kidneys and eyes."
Ms Nasreen alleged that the Indian Foreign Minister, Pranab Mukherjee, had exerted "great mental pressure" on her to leave the country.
"I settled in Calcutta where I was living peacefully in a Bengali milieu," she wrote.
"I was very active helping oppressed women and writing feminist and humanist literature.
"But just because a few Muslim fundamentalists objected to my being in this country, I was first confined in Calcutta and then moved to Delhi," she said.
The author also alleged that the Indian government - and the state government of West Bengal - were only concerned with their "Muslim vote bank".
"In order for the politicians to secure this Muslim vote bank, I had to be locked up and as a consequence, my health was irreparably destroyed," she said in the e-mail.
Last month, Ms Nasreen was rushed to a hospital in Delhi after her blood pressure dropped because of an overdose of medicines.
Correspondents that despite protests by Muslim groups, Indian authorities have extended her visa regularly, but not allowed her to leave the house, which is guarded round-the-clock by police.
The BBC's Subir Bhaumik in Calcutta says that it is not clear how soon she will leave India - or which country she will go to.