A main road in Haverfordwest town centre has been closed off while police investigate a serious incident.
The road between the Morrison's Roundabout and Salutation Square is closed off.
A Dyfed-Powys Police spokesman said: "At approximately 00.40hrs on 12th April 2014 an unconscious man was discovered in the carriageway on Cartlett Road, Haverfordwest, by a passing motorist.
"Police are currently investigating the circumstances.
"Dyfed Powys Police are appealing for witnesses that may have been in the area at this time and can provide any information regarding these circumstances – anyone with any information is asked to call 101.
"At this time the carriageway at Cartlett Road remains closed until further notice, and diversions are in place."