Five people have now been arrested for repeatedly gang-raping and extorting money from a young Japanese tourist held hostage for nearly a month in a basement close to a famous Buddhist shrine in India, officials said Sunday.

The 22-year-old's ordeal began in Kolkata, capital of West Bengal state, where she was befriended by three local men shortly after arriving on November 20, one of the city's top police officers told AFP.

The men, one of whom spoke Japanese, first managed to persuade her to withdraw around $1,200 dollars in cash before travelling with her to the holy shrine of Bodh Gaya in the neighbouring state of Bihar.

There she was then handed over to two brothers who locked her in a secluded underground room and repeatedly raped her for nearly a month.

The two brothers, who were working as tourist guides, were arrested on Friday and taken to Kolkata where they appeared in court late Saturday. A magistrate ordered that they be remanded in custody until January 9 so the victim can take part in an identification parade.

Kolkata joint police commissioner Pallab Kanti Ghosh said the other three people were being held on suspicion of extorting money from the victim and then handing her over to the alleged rapists.

"We have arrested three people who befriended the victim in Kolkata. They have been charged with common conspiracy and intention to kidnap and rape," the commissioner said.

"The men managed to extort 76,000 rupees ($1,200) from her and convinced her to travel to Bodh Gaya with them in their car."

The woman managed to escape from Gaya and reached the Hindu holy city of Varanasi where she met some Japanese tourists who helped her contact the consulate in Kolkata.

Although it was not immediately clear when her ordeal ended, police said she filed the police report in the last week of December.

"(When) we came to know of the incident... we assisted her in registering the complaint with the police," Japan's consul-general in Kolkata, Kazumi Endo, told AFP.

The case is the latest in a string of high-profile sex attacks reported across the country that have highlighted the frightening levels of violence against women in the world's second most populous country.

India has faced intense scrutiny over its efforts to curb violence against women following the fatal gang rape of a medical student in New Delhi in December 2012, which sparked global outcry.

While there has been outrage over sex attacks targeting middle-class women since the Delhi gang rape, this latest case went largely unnoticed, with major newspapers restricting coverage to small news items.

The gang-rape of rural women also rarely garners media attention in India.