The rape and murder of a young woman in New Delhi in December followed by two attacks on foreign female travellers has altered how tourists view India and led to a sharp fall in the numbers of foreign tourists, especially women, a study says.

In the three months since that attack, the number of foreigners travelling to India has dropped by 25 per cent, according to the study by the New Delhi-based Associated Chambers of Commerce and Industry. The number of female tourists has dropped by 35 per cent, the study released late Sunday said.

The gang rape of the 23-year-old university student on a bus in the heart of the Indian capital shocked a country often inured to such sexual violence. It brought hundreds of thousands of angry citizens out in the streets to demand more safety for women and harsher laws to deter the perpetrators of such acts.

The study surveyed 1,200 tour operators from across the country who said that "concerns about the safety of female travellers" had affected how foreign travellers viewed India.

Notorious attacks on women

Since the December gang rape there have been two widely publicized incidents where foreign female travellers have been attacked.

Last month a Swiss woman was gang-raped in central India as she and her husband camped in a remote forest. In the second incident a young British woman says she was forced to jump out of the window of her hotel room to avoid a sexual attack in Agra, the city that is home to the Taj Mahal.

According to the study, the three incidents have hurt tourism, and nearly 72 per cent of the tour operators said cancellations of holiday bookings came mostly from women tourists, most of them from Britain, the United States, Canada and Australia.

The study said that travellers planning trips to India had instead opted for other Asian countries such as Malaysia, Thailand, Indonesia and Vietnam.

The winter months from November to March mark the peak tourist season in India.

According to India's Tourism Ministry, 6.6 million foreign tourists visited India in 2012, earning the country $17.74 billion in foreign exchange.