Arundhati Roy, the Booker Prize winning author, has accused Mahatma Gandhi of discrimination and called for institutions bearing his name to be renamed.
Speaking at Kerala University in the southern Indian city of Thiruvananthapuram, Roy, 52, described the generally accepted image of Gandhi as a lie.
"It is time to unveil a few truths about a person whose doctrine of nonviolence was based on the acceptance of the most brutal social hierarchy ever known, the caste system ... Do we really need to name our universities after him?" Roy said.
The caste system is thousands of years old but still defines the status of hundreds of millions of people in India. So-called untouchables, or Dalits, continue to suffer discrimination.
The author's comments provoked immediate outrage from descendants and some scepticism from historians.
"Being outspoken is one thing but being so blasé about your ignorance is quite another," said Tushar Gandhi, Mahatma's great-grandson. "It's just an attempt to get publicity."
Professor Mridula Mukherjee, an expert in modern Indian history at Jawaharlal University in Delhi, said Roy's criticism was misplaced.
"Gandhi devoted much of his life to fighting caste prejudice," he said. "He was a reformer not a revivalist within the Hindu religion. His effort was in keeping with his philosophy of nonviolence and bringing social transformation without creating hatred."
Roy's comments come amid a series of rows over the study and representation of Indian history. The appointment of a little-known academic to the head of a national research body has raised concerns that the new Hindu nationalist government in India may try to promote an ideological version of the country's past.
The Bharatiya Janata Party (BJP), led by Narendra Modi, won a landslide victory in May. When last in power, between 1998 and 2004, the BJP prompted controversy with its efforts to cut out what it saw as Marxist or western influence on textbooks.
Professor Yellapragada Sudershan Rao took up his post as chair of the Indian Council of Historical Research last month.
Rao immediately caused controversy by criticising alleged Marxist influence on Indian historical studies and western-inspired research methods.
He also said he believed the Hindu literary epics, the Ramayana and the Mahabharata, were historically accurate accounts of real events.
Salil Tripathi, a columnist in Mint, a local newspaper, wrote: "He appears to believe that history is shaped by both faith and reason. Faith matters, of course, but faith is part of a culture, it should not dictate history. Faith is about unquestioned belief; history is about facts and reality."