An investigation has begun into the death of a senior detective in a Dublin Garda station last night.

The dead officer, who was in his 50s and one of the most seasoned detectives in the force, was found dead in an office at Ballymun Garda station, north Dublin.

No foul play is suspected and nobody else is being sought in connection with the officer’s death. The incident is being treated as a personal tragedy.

A Garda-issue firearm has been taken from the scene for analysis.

While no foul play is suspected, the Garda Siochana Ombudsman Commission (Gsoc) is legally obliged to investigate all such cases.

The Garda watchdog investigates complaints made by the public against members of the force.

It also investigates any case where death or serious injury to any person has occurred at or around the time they have been in contact with members of the Garda.

That includes deaths or serious injuries sustained while suspects are in custody or have just been released from custody. Gsoc must also investigate any injury or death occurring in a Garda station, as was the case last night, or in a Garda vehicle.

In all such cases Gsoc, assumes the role of the investigating agency, including sealing off a scene and forensically examining it and interviewing witnesses.

A postmortem was due to be carried out on the remains of the officer.

Garda sources said there was a deep sense of shock across the force at the death of the officer, who was well-known nationally and highly-respected.

He played a leading role in the investigation into the fatal gun attack in the Regency Hotel, Whitehall, north Dublin, two years ago.

That incident, carried out by a group of armed men at a boxing tournament weigh-in, sharply escalated the Kinahan-Hutch feud which was just beginning at the time.

Dublin man David Byrne was killed in that attack and a murder trial is currently underway at the Special Criminal Court in relation to that shooting.

The officer who died last night was a leading figure in the investigation that resulted in the trial currently underway.

He had for most of his career been at the forefront of investigations into homicides and organised crime generally.