The agency issued a statement in this regard.
"A case was registered by CBI on Oct 8 against the former minister U/S 323 and 376 of IPC on the request of Rajasthan government and further notification from the government of India, it said.
"This case relates to allegations levelled by the complainant (victim) against the accused for causing hurt and committing rape on Sep 11," the statement said.
CBI had taken over the investigation of the case, earlier registered by Rajasthan Police vide FIR No.292/2013 at police station Sodala in Jaipur, the state capital.
The accused will be produced Saturday in the designated court at Jaipur.
Nagar, 53, resigned from the state cabinet two days after the FIR was registered Sep 17.
He was called to a government circuit house for interrogation by CBI Friday.
"He was interrogated from 11.30 a.m. to 6 p.m. today (Friday). After he could not give satisfactory answers to CBI questions, he was arrested. He will be produced before a court tomorrow (Saturday)," said a source close to the investigation agency.
Nagar represents Dudu constituency in Jaipur district.
In her police complaint, the 35-year-old woman alleged that Nagar called her to his official residence on the pretext of giving her a government job and raped her Sep 11.
Two other legislators of the ruling Congress party, Malkhan Singh and Mahipal Maderna, were suspended in December 2011 following allegations of sexual exploitation and murder of government nurse Bhanwari Devi.
--IANS (Posted on 26-10-2013)