At least five deaf and mute orphan girls were said to have been raped by members of staff at a residential home for speech therapy near Jaipur, India.

The girls, aged between 12 and 17, were reportedly sexually assaulted and beaten up by staff at the Awaaz Foundation, a government-funded NGO in Kanota outside Rajasthan's state capital.

Abuse occurred between July and March. Authorities at the residential home were warned of the abuse in January.

Police arrested five people, among them a warden and a clerk who reportedly confessed.

Ashok Prajapat, 28, a warden at the foundation's boy section, was accused of sneaking into the female dormitory at night, gagging his victims, taking them to a separate room and abusing them. He is accused of raping a girl twice and another eight times since July last 2012.

The institute was home to 16 girls and 100 boys.

The foundation's clerk Suresh Bairwa has been arrested for rape and security guard Mahesh Mali has been held on sexual assault charges.

"Prajapat and Bairwa led us to the places in the building where they gagged the girls and raped them," a police officer told the Times of India.

Bairwa's wife Geeta, who was the warden in charge of the female section, has also been taken into custody, as she allegedly conspired with the rapists and beat up one of the girls after she complained to the centre administrator about abuses.

Administrator Alpana Daswan has been arrested for failing to report the crime.

According to India's National Crime Records bureau, a woman is raped every 20 minutes and in many cases victims are minors.

The country's record for sex crimes against women rose up the news agenda after the case of a 23-year-old student who was gang-raped on a Delhi bus in December.