Police have finished scene examinations on a Tawa street where a man was found with serious head injuries.

The 49-year-old from Porirua remains in Wellington Hospital after he was found lying next to the road by police about 11.30 Saturday night.

Detective Senior Sergeant Grant Ferguson says they're looking at a couple of locations on Rossiter Street..

He says the focus now is trying to work out what the victim was doing, and how he got the injury.

Grant Ferguson says Rossiter Street is usually a quiet cul-de-sac in a nice area.