Mystery surrounds the death of a man who was found critically injured at a unit complex.

Emergency services were called to Ryan Street, West End, in Brisbane’s inner south, about 4.30am on Saturday to reports a man had been found unconscious.

Police arrived to find a 50-year-old West End man unresponsive with critical injuries.

Know the news with the 7NEWS app: Download today

He was later pronounced dead at the scene.

Police have launched a sudden death investigation and are examining the unit complex.

There is no ongoing concern to other members of the community in West End, police said.

Investigators are appealing to anyone with information that may assist investigations to come forward.