The man convicted of killing Christchurch woman Renee Duckmanton has had his appeal denied.

33-year-old butcher Sainey Marong was found guilty of the murder in February, and sentenced to a minimum 18 years in prison.

Before a panel of judges last month, he appealed his sentence on the grounds of temporary insanity.

The court found none of the factors introduced by the appellant to be valid.

They dismissed the appeal  and Marong's application to introduce more evidence was declined.