The victim met the District Magistrate of Mathura B Chandrakala yesterday and narrated her ordeal and on the DM's instruction police registered the case today.
The incident happened on May 28 when the accused brothers Chotu and Pramod went to the victim's house when she was alone and raped her while their uncle Dhammo stood guard outside the house with a gun, police said.
"The rape case has been registered against three persons and probe has started," Deputy SP, Rajendra Prasad Yadav said.
She had also alleged in her complaint that police did not file her FIR then.