Dorset Police were called just after 5pm on Thursday last week (10 Sept) by the ambulance service to a report of man requiring medical assistance following a suspected drugs overdose at an address in St Georges Road in Dorchester.
The man, aged in his 40s, was taken to hospital in a life-threatening condition. His family has been informed.
A 25-year-old man from the Weymouth area and a 44-year-old local man have been arrested in connection with the incident. They have both been released on police bail pending further enquiries.
An investigation is continuing in order to establish the full circumstances of the incident.
A cordon had been in place at the address to allow for an examination of the scene.