Sainey Marong appeals conviction for murdering Christchurch woman Renee Duckmanton

Sainey Marong was found guilty at the High Court in Christchurch of murdering sex worker Renee Larissa Duckmanton. Photo / Pool

Gambian butcher Sainey Marong is appealing his conviction for murdering Christchurch woman Renee Duckmanton.

Marong, 33, was found guilty of murdering the sex worker after a High Court trial in Christchurch in February.

He was jailed for life with a minimum non-parole period of 18 years.

However, he filed an appeal against his conviction in May, the Court of Appeal confirmed today.

No hearing date has been set.

It's understood that Marong will represent himself.

During the harrowing two-week trial, Marong admitted strangling Duckmanton in May 2016 after picking her up from the city's red light district before setting her body on fire and dumping her on a country roadside.

But he denied that he meant to kill her, and had no murderous intent, claiming he was insane at the time, suffering mental impairment and delusional, psychotic thoughts which began after voluntarily stopping his insulin medication early in 2016.

The jury, however, sided with Crown and its "overwhelming" evidence, dismissing Marong's claims that he had been "disconnected from reality" at the time he killed Duckmanton, and that from May 6-17, he was poisoned by kidney failure that resulted in urine "travelling in my brain".

A psychiatrist and a psychologist, who both assessed Marong before he stood trial, concluded that he did not meet the criteria for a defence of insanity.