Yudhishtir was arrested and produced in a court here last evening. Three other accused are still absconding, SP Crime Aditya Verma said.
Additional Chief Judicial Magistrate Arun Kumar sent him to judicial custody till March 15.
The probe in the case was transferred to the crime branch on February 20 following Mahima's suicide.
Mahima's mother had alleged that some influential persons in the city were involved in the wrongful confinement of her husband and son.
While Ved Prakash had returned home, the whereabouts of son Akshay have not been ascertained yet.