Muhammad Waseem, the younger brother of Baloch who was arrested for murdering her, has confessed to his crime.
According to police, further evidence was needed to corroborate the confession and investigate if any other was also involved in it.
"Waseem was taken to Lahore on Friday for tests. The results of polygraph and DNA tests will be available next week," according to senior police officer Azhar Akram.
Waseem is in police custody on five-day remand.
However, so far no decision has been made to interrogate Muhammad Aslam, another brother of Baloch who is junior commissioned officer in the army.