Mrs Chioma Nwosu, a judge at Benin Division of Court of Appeal, was kidnapped on Wednesday.
A police officer was killed during the incident along Benin-Agbor Highway, police said.
The judge was abducted on Wednesday morning while heading out for an assignment.
Edo State police commissioner Mr Mohammed Danmallam, said rescue efforts had commenced for the senior judge and a manhunt launched for the attackers.
The police chief said the abductors ambushed the judge and her police orderly on the highway and opened fire. The officer died on the spot.
A picture allegedly of the slain officer laying lifeless on the highway had made social media rounds on Wednesday afternoon.
The abduction came a week after a judge attached to Akure Division of the Federal High Court was as abducted on his way back to base from Abuja.
Mr Abdul Dogo was freed three days after his abduction on October 25. His driver that was kidnapped alongside him was also released afterwards, amidst reports that they parted with huge ransoms.
Danmallam urged members of the public to assist the police with information that may lead to Nwosu’s release and arrest of the suspects.