Falling branch kills NSW bike passenger

A woman has been killed in an apparent freak accident involving a tree branch that fell on a motorbike in the NSW Riverina region.

The 62-year-old was riding as the pillion passenger with a 57-year-old man on the Snowy Mountains Highway near Tumut about 3.10pm Saturday.

NSW Police said a falling tree branch struck the bike and the woman was killed at the scene.

The driver suffered multiple injuries and was taken to Tumut District Hospital, where he's undergone mandatory testing.

Local officers will investigate the incident further, police said.