The family of Christchurch woman Libby McKay could fight for a new inquiry into her death - after a coroner was unable to determine the exact circumstances surrounding it.

The 27-year-old died after falling from a speeding ute in Hornby in June 2013.

At the inquest into her death there was contention over whether she was pushed from the vehicle by her then partner Mike Brown, or whether she rolled out of the car following a short argument.

Coroner David Crearer says questions still remain over the death, and if Mike Brown returned to New Zealand, a fresh inquiry could be opened.

Libby McKay's family would need to present a petition to the Solicitor General to request an inquiry.

Mike Brown lives in Australia.