The woman law student, who had levelled charges of sexual misconduct and harassment against UP BJP leader Chinmayanand, was taken into custody by the Special Investigation Team (SIT) on Tuesday.
The woman had posted a petition for anticipatory bail in the district court when the SIT picked her up before the petition could come up for hearing.
The 23-year-old woman was taken into custody on charges of extortion and blackmail. Chinmayanand had accused her and three men of demanding Rs five crore from him.
The three men - two of whom are the woman's cousins - have already been arrested on Friday and sent to jail.
Two of the men, Vikram and Sachin, were also taken on remand by the SIT on Tuesday and it is believed that the SIT will question the boys and the woman face-to-face.
The woman, on Monday, had put up a bail application in the Allahabad High Court but the same was rejected and the high court asked her to appeal in the district court.