An Amaroo man has been charged after a woman was sexually assaulted in Gungahlin.

Police will allege a man sexually assaulted the victim, a 29-year-old woman, in a black Holden Calais during the early hours of Wednesday 1 August.

It's believed it happened near a red brick building with temporary fencing around the site.

The 35-year-old man has been charged with three counts of sexual intercourse without consent.

Police want anybody who may have seen a black Holden Calais driving around Gungahlin at 4am last Wednesday to call Crime Stoppers on 1800 333 000.