The plane crashed into a paddock near the intersection of Walker and Sunnybrae roads just before 10.30am this morning. The area has now been cordoned off, as police major crash officers travel to the scene to begin an investigation.
Authorities say investigators from the Australian Transport Safety Bureau are also on the way. It is believed that at least one commercial flight was diverted from the area as the emergency unfolded.
Earlier this morning there had been flight delays in and out of Mount Gambier due to fog, but authorities say its too early to know if this was a factor in the accident.
The crash comes less than a month after another South Australian aviation tragedy. A Rossair plane crashed near the Riverland town of Renmark on May 30, claiming the lives of three experienced pilots. An investigation into that accident is still underway.