DOZENS of STAR Group police officers surrounded a home in the Adelaide Hills and the entire area was cordoned off as police negotiated with a man inside a unit for more than four hours on Sunday night.

The Advertiser understands police began intense negotiation with a resident of a unit in Main Rd, Blackwood just after 9pm on Sunday.

It is understood the man, believed to be a high-ranking police officer, had threatened self harm and that he intended to burn his house down.

Police officers, detectives, ambulance officers and CFS crews all attended.

media_camera STAR Group officers at Blackwood as the siege develops. Picture: Mark Brake

Main Rd between East Terrace and the Blackwood roundabout was blocked off to all traffic and the public was being kept well away from the area.

Police confirmed there one man was inside the home.

The man emerged from his house without incident about 12.15am.

A police spokeswoman said he was detained under the Mental Health Act and was taken by ambulance to the Flinders Medical Centre.

“We thank residents for their patience,” she said.

Main Road, Blackwood was closed between East Terrace and the Blackwood roundabout, but has since reopened.

If you or someone you know needs help with suicide or self-harm issues, call Lifeline on 13 11 14

media_camera Police officers at the scene of the siege. Picture: Mark Brake

media_camera STAR Group officers at the scene in Blackwood. Picture: Mark Brake