Bollywood superstar Salman Khan has caused public uproar after he said shooting his upcoming movie was so gruelling that he felt like a woman who had been raped.

The public fury and social media backlash has been so great that Khan's father, Salim, apologised on his son's behalf and pleaded with the public to forgive him.

India's National Commission for Women also demanded that Khan explain his comments within seven days or be hauled before the state-appointed panel.

By Wednesday, Khan had said nothing about the remarks he made while speaking with journalists over the weekend about portraying a professional wrestler in the new film Sultan.

The actor's rape analogy was widely criticised on social media sites in India, where sexual violence against women is rampant.

While the topic is still taboo in some places, a protest movement has emerged in cities with demand for better safety for women and harsher punishment for rapists.

The National Commission for Women's chief Lalitha Kumaramangalam said: "It's not only a wrong statement, it's very irresponsible and callous for a man whose fame and wealth are based on the adoration of his female fans."

Salim Khan tweeted: "To err is human to forgive divine." And in another tweet, he said: "Nevertheless I apologise on behalf of his family his fans & his friends. Forgiveness is to pardon the unpardonable or it is no virtue at all."

The problem of sexual violence has long gone unrecognised in India, until the gang rape and mutilation of a young woman on a moving bus in December 2012.

Public protests in New Delhi and other cities prompted the Indian government to strengthen laws for punishing those convicted of sexual crimes in 2013, as well as for prosecuting authorities who fail to investigate complaints.

But strong social stigmas still prevent many victims from coming forward, and many women's rights activists say more awareness and education of the issue are needed.

Khan's remark was considered particularly damaging given his immense popularity as a leading romance and action star in the Bollywood film industry.