Police were called to a derelict building off Andover High Street at around 11.17am this morning (Wednesday), where officers discovered a cannabis grow.
As officers arrived, three men at the scene attempted to leave the area. One of the men is believed to have fallen during this time, sustaining a serious head injury. He was detained by police before being taken to Southampton General Hospital for treatment.
Two other men, aged 27 and 29, were arrested nearby on suspicion of being concerned in the supply of cannabis. They remain in police custody at this time.
Hampshire Constabulary has confirmed enquiries remain ongoing.