The family of a murdered Indian gang-rape victim will not rest until her killers are hanged, her brother said in an interview published on Monday.

"The fight has just begun. We want all the accused hanged, and we will fight for that, till the end," the brother told the Indian Express.

Six men are facing murder charges after allegedly luring the 23-year-old onto a bus in New Delhi on December 16 and then taking it in turns to rape her before throwing her out of the moving vehicle.

She died of her injuries in a Singapore hospital on Saturday and was cremated back in Delhi on Sunday morning.

Speaking to the same newspaper, the young woman's father spoke of the impact of the tragedy on the family, saying her mother is consumed by grief.

"My wife had hardly eaten in the last two weeks," said the father.

"She was exhausted... I think she was not ready to face the shock of our daughter's death, despite doctors always telling us that she was serious. She cried intermittently all of Saturday, but it got worse on the flight back home."

The father said he too was struggling to accept the news.

"It is too painful. I have not gone inside her room. She was born in this house. Her books, clothes they are all here," he said.

"It is hard to believe I will never hear her voice again, she will never read books to me in English again."

India does have the death penalty on its statute book although executions are rarely carried out.

Mohammed Ajmal Kasab, the only surviving gunman of the 2008 Mumbai attacks, was hanged last month but it was the first execution for eight years.