The woman, a mother of two, alleged that the accused got married to her in January this year despite already being in a wedlock, SP (City) Sri Kant Yadav said.
He repeatedly forced her into physical relationship after which she became pregnant, the victim alleged, claiming that she gave birth to the accused's child 15 days back.
An investigation into the allegations has been ordered and a manhunt has been launched to nab the politician, Yadav said.