A chart-topping Indian rapper known for his sexually explicit lyrics has been caught in a backlash against sexism and misogyny after a deadly gang rape that shocked the nation.

Honey Singh, whose hits include My Home My Village, saw his New Year's Eve concert in New Delhi cancelled following an online campaign over lyrics that incite violence against women.

His 2007 track Prostitute refers to him having violent sex with a woman after he forces her to "dance naked" and includes the line: "You will scream and run but where can you go... I will take your life."

Amid low-key New Year's celebrations following the shocking gang rape on December 16, the upmarket Bristol Hotel in a suburb of New Delhi cancelled the show, an employee said.

The popular star, who sang in Bollywood films last year and has several top 10 hits, told the Hindustan Times he himself had called off the performance to "express my grief for the unfortunate girl".

The furore over the rap star comes as the country comes to terms with the incident in which a 23-year-old medical student was repeatedly assaulted and violated with an iron bar while being driven around in a bus for 40 minutes.

She died from internal injuries in a Singapore hospital at the weekend.

Extreme sexual violence and gang rapes are commonplace in India, but the case brought simmering anger - particularly among young urban women - to the boil and led to violent protests in the capital.

Home minister Sushilkumar Shinde said six suspects arrested after the crime risked the death penalty if found guilty and the case against them appeared very strong.

"We have a solid case with very good evidence... a magistrate has recorded the victim's dying declaration and we have a prime witness, the girl's friend, who has identified the rapists," Mr Shinde told The Economic Times newspaper.

The victim's boyfriend, whom friends said she intended to marry, tried to prevent the rape and was likely to give crucial evidence during what was expected to be a fast-tracked trial.

Police are to file charges and present their evidence against the suspects - five men and a minor - on Thursday.

Delhi police have said their probe is almost complete, pending the arrival of an autopsy report from doctors in Singapore and the conclusions of forensic experts.

AFP