Police said head constable Narinder Singh's body was found early this morning, just a few yards away from Aujla's election office.
Police said the constable had left Aujla's office on the pretext to answering the nature's call but allegedly shot himself with his service weapon. The police rushed to the spot and took control of the body.
SAD-BJP candidate Rajinder Mohan Singh Chhina, however, demanded a high-level probe into the incident, saying the constable died under "mysterious circumstances".
"A high-level probe must be initiated...," he said.
BJP leaders, including former state unit President, Kamal Sharma, demanded the security cover to Chhina should be enhanced.
The bypoll to the Amritsar Lok Sabha seat, which will be held simultaneously with the Assembly polls on February 4, was necessitated after Congress leader Amarinder Singh resigned to protest the Supreme Court's verdict on the SYL canal issue.