A cement lorry driver has been left in hospital with serious head injuries after the vehicle tipped over near Haddenham.
The lorry was travelling from Aylesbury towards Thame on the A418 when it crashed at the roundabout junction with Pegasus Way.
The driver, a man in his 30s, was taken to the John Radcliffe Hospital in Oxford for treatment.
The incident happened at around 10.10am on Saturday (July 27).
Anyone with information should call PC Michael Sapwell on 101 or Crimestoppers anonymously on 0800 555 111.