A 23-year-old police constable posted on sentry duty at the office of the elite anti-terrorist force - OCTOPUS - at Begumpet area here died on Sunday evening in an incident of "accidental firing", police said.

Shiva Kumar, was on sentry duty at the office of Organisation to Counter Terrorist Operations (OCTOPUS) and there was an "accidental firing" incident resulting in his death, Assistant Commissioner of Police Venkateshwerlu said.

"He was relieving his duty at around 6 PM when there was an accidental firing from the 9 MM pistol (service weapon) he was carrying," the police officer told PTI.

Kumar, a special police constable, was attached to 13th battalion of Telangana Police and had been posted at OCTOPUS office since 2013, the ACP said, adding the constable hailed from Adilabad district of the state.

Panjagutta Police registered a case of suspicious death under section 174 of CrPC.

They said investigations were underway.