A teenager was allegedly forced to strip and molested by police when she refused to pay a bribe to lodge a rape complaint in northern India, officials said Wednesday.

"The girl complained that the station house officer took her into a room and asked her to remove her clothes, so he could confirm if she had been sexually assaulted," on Sunday, the region's police chief Lalit Kumar Singh said.

The victim, 18, "alleged she was later molested by the officer, who had demanded 50,000 rupees (800 dollars) to lodge the rape complaint," he added.

The Times of India reported the girl's age as 14, and said the alleged assault occurred after her father, who had taken her to the station, refused to pay the bribe.

The police launched a probe against the officer, in the Kushinagar district of Uttar Pradesh state, after the father complained to the police superintendent on Tuesday, the report said.

Singh said Wednesday the police had charged the officer with molestation, and arrested a suspect of the original rape.

Sexual violence has been a focus of public attention in India since the fatal gang rape of a student on a bus in New Delhi in December triggered mass protests.

But activists say little has changed in attitudes towards sexual assault, and attacks on women and girls continue unabated.

Campaigners have said police officers' patriarchal and misogynist mindset deters victims from reporting sexual violence.