Police are investigating an incident which has left a man in a critical condition after he was allegedly assaulted in Darwin earlier today.

Police responded to a report of an alleged assault at a residential premises in Darwin City at approximately 2pm where they found a 52 year-old man in an unresponsive condition.

The man was transported to the Royal Darwin Hospital where he remains in a critical condition.

Police have taken a 50 year-old man into custody after he allegedly became aggressive towards Police and assaulted a member.

Investigations into the circumstances surrounding the incident continue.

There are no further details available at this stage.

Police are appealing to anyone who may have information in regards to this incident to contact them on 131 444 or anonymously via Crime Stoppers on 1800 333 000.