A 25-year-old woman has been accused of deliberately crashing a car into her uncle in an incident that caused him to lose a leg.
The crash victim, 40, suffered serious injuries when the car pinned him against a pole in the crash on Wakefield Quay in Nelson at 7.40am.
He was taken to Nelson Hospital in a "very serious" condition, where he was believed to be undergoing surgery to amputate his leg.
She allegedly drove away from the crash scene before emergency services arrived, police said.
Detective Senior Sergeant Wayne McCoy said the woman was taken to Nelson Police Station by her family after investigators went to her last known address this morning.
She had been in a dispute with her uncle some time prior to the crash, he said.
The woman was due to appear in Nelson District Court on a charge of wounding with intent to cause grevious bodily harm at 2.15pm.
Police were still interviewing multiple witnesses to the crash, Mr McCoy said.