The police said the case was registered under sections related to cheating and forgery.

A case has been filed against the rape survivor who has accused Uttar Pradesh BJP lawmaker Kuldeep Singh Sengar for producing a forged age certificate to prove she was a minor.

The first information report, filed on court orders, also names her mother and an uncle. The case was registered against the three on a complaint by the father of another rape accused, who is in jail, said senior police officer Harish Kumar Thursday.

He said complainant had alleged that the survivor, her uncle and mother had procured a forged age certificate to implicate his son Shubham in the rape case, said Mr Kumar.

The police said the case was registered against the family members under sections related to cheating and forgery.

The complainant had moved the court saying the school transfer certificate, purportedly made by Raebareli school and produced as the age certificate, was forged to frame his son, police said.

The survivor's uncle is presently in jail in connection with another case. The complainant's wife and son are accused in the rape case and have been in jail since April along with the main accused, BJP legislator Kuldeep Singh Sengar.

Sengar, a four-time lawmaker from Unnao, was charged by the CBI with raping the girl at his residence in Makhi village on June 4 last year.

The girl was again abducted and raped by a separate group of accused, allegedly including complainant's son Shubhan Singh, his driver Naresh Tiwari and one Brijesh Yadav between June 11 and June 20, 2017.

The complainant, Harpal Singh alleged that the rape survivor had an affair with a man named Awadesh Tewari, with whom she had eloped in September 2017, and returned sometime later.

After she returned, her family had begun persuading his son Shubham to marry her, the complaint said.

When Shubham refused to marry her, the family filed a case against him and his mother on charges of kidnapping as well as various offences under the Protection of Children from Sexual Offences (POCSO) Act, alleged Haripal Singh.

He also alleged that the rape survivor's family had forged her age certificate with a fake date of birth, purportedly issued from a school in Raebareli as proof.

Both the education department official and the school principal have denied signing the certificate, Haripal Singh claimed.

The Yogi Adityanath-led BJP government's "inaction" against the party lawmaker in the case had drawn scathing criticism from the Allahabad High Court.

The state government had subsequently transferred the case to the CBI nearly 10 months after the alleged crime took place.