Guwahati: An official of PSU major Oil India Limited (OIL) was found dead on Tuesday under mysterious circumstances at his official residence at Duliajan in upper Assam’s Dibrugarh district.

The body of OIL’s technical audit officer Bhaskar Bora was found after breaking open the locked room of his residence on Tuesday, said a police official.

The main door of Bora’s house was locked from outside when the police and officials of OIL reached his residence, the official said.

The body has been sent to the Assam Medical College and Hospital (AMCH), Dibrugarh for post-mortem examination.

According to police, no injury mark was noticed on his body and the reason behind his death is yet to be ascertained.

Police have registered a case at Duliajan police station in connection with the incident and the investigation is underway.

“We have registered a case of unnatural death. But preliminary investigation suggests it is a case of suicide. We will be able to confirm only after the post-mortem report is available,” said the police official.