Police have cordoned off the entrance of the Billy Trail on Hayling Island this morning.
Emergency Services rushed to the scene just after 11am this morning and a Specialist Hazardous Area Response Team were called from 30 miles away in Otterbourne near Winchester to assist.
A South Central Ambulance Incident Response Unit and two paramedic officers in Land Rover Discoveries were seen entering the off road track.
An ambulance left the scene just after 1pm escorted by police officers. It is not known if the ambulance contained a casualty.
The Ambulance had to reversed down the seven mile track. An officer was seen getting into the ambulance that drove off.
Officers stood guard for most of the morning with cordon tape blocking the entrance to the trail.
Communications Manager for South Central Ambulance Service, Michelle Archer, refused to comment on the ongoing incident.