"The three cops were taken into custody after their involvement was established in a case registered in Sher Garhi police station earlier this week," a police spokesman said.
During the course of investigation in the case, it was found that a police constable was in touch with anti-national elements, he said.
Further investigations revealed two more constables of the state police were also involved in such activities, the spokesman said.
"These three constables have been taken into custody and their conduct is being scrutinised," he added.
However, the police officials were tight-lipped about the case and refused to give any further details.