A team led by the additional superintendent of police V K Gaur recorded the statements of the woman and her son for about 90 minutes at their residence, a police spokesman said.
The woman's 17-year-old son cooperated with the investigating team for recording of his statement, he said.
His statement was an important piece of evidence as he had reportedly received calls offering a huge sum of money to drop the case allegedly by a close aide of Nagar.
Nagar, former minister of state for Dairy and Khadi, resigned on September 19 after he was accused of raping the woman at his official residence here.
The former minister denied the charge claiming that his political adversaries had hatched a conspiracy to tarnish his image.