The law enforcer, whose name was withheld pending the investigation, is now in the custody of the provincial police after he was linked to the kidnap-slaying of Concepcion Azurin-Lumanglas, 50, assistant provincial parole and probation officer of the Department of Justice here.
Senior Superintendent Jude Santos, provincial police director, said the possible involvement of the policeman, who is assigned to a southern Isabela town, cropped up after the van used by the seven kidnappers was traced to him.
Police said they found the body of Lumanglas, a resident of Capitol Hills, Barangay Alibagu here, in a grassy area near the national road in Naguilian town last Friday afternoon.
Santiago City policemen intercepted the kidnappers van last Friday and arrested its two passengers, whose names were also withheld.
Police said Lumanglas was stabbed several times and strangulated.
Probers said her killing could be work-related.