Four members of a family died on Friday after consuming toxic food in Toba Tek Singh.
According to police, the deceased included a mother and her three daughters.
The bodies have been taken into custody.
Police further said they have are investigating the incident from all angles to determine whether it was a murder or suicide.
"We are also collecting infromation from the locals in this regard,” police added.
The bodies have been shifted to a hospital for post-mortem, police said.