South Dakota Attorney General Jason Ravnsborg investigated over fatal car crash

Jason Ravnsborg said he initially believed he had struck a large animal on a rural stretch of road

The attorney general of the US state of South Dakota is being investigated over a fatal car crash, after he reported hitting a deer but later discovered a man's body at the scene.

Jason Ravnsborg, 44, told police he had hit a deer while driving home from a fundraising event for the Republican Party on Saturday night.

But he returned to the scene on Sunday to find the body of Joseph Boever, 55.

Mr Boever's family have expressed fears of a possible hit-and-run cover-up.

They say they were not contacted by investigators to identify Mr Boever's body until almost 22 hours after it was discovered.

The South Dakota Department of Public Safety said the investigation would be handled "as we would any other fatal crash".

Mr Ravnsborg said in a statement on Monday that he had called police immediately after the incident on a rural stretch of US Highway 14 late on Saturday.

He said he stopped and used the flashlight on his phone to look around his vehicle in the dark, but saw nothing other than damage to his car and believed he had hit a large animal.

He added that was co-operating with the investigation, while offering his "deepest sympathy and condolences to the family of Mr Boever".