The courts have released CCTV footage of Sainey Marong, 33, and Renee Duckmanton, 22, from the night he murdered the Christchurch sex worker. (Video first published on February 26, 2018)

Chilling video footage of a murderer driving his car to dump his victim's body – and the victim's last movements – has been released.

Sainey Marong, 33, was found guilty of murdering Christchurch sex worker Renee Duckmanton in the High Court at Christchurch last week.

He told the court he strangled the 22-year-old during a dispute after having sex in the back of his car on May 14, 2016. He dumped her body on the side of a rural Rakaia road the following day and set her on fire. He claimed he was insane at the time.

Sainey Marong was seen filling up his car on the night the body was dumped.

CCTV footage of both Marong and Duckmanton between May 14 and 15, 2016 has been released by the court.

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* Killer 'insane' when he strangled sex worker

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* 'Distinctive' tail light helped police track suspect

At 6.47pm on May 15, Marong – a Gambian-born butcher from Ilam – can be seen pulling off State Highway 1 into the Rakaia Mobil station in his Audi A4.

SUPPLIED Renee Duckmanton was last seen alive walking down Peterborough St, as captured by a private security camera, on May 14, 2016.

Wearing a blue, black and white striped shirt he refuels his car, heads inside the station and pays the woman behind the counter and gives her a thumbs up. He then stops, turns around and gives her what appears to be some coins before leaving.

He gets back in his car and heads towards Ashburton, but a short while later the car drives past Mobil again heading in the opposite direction. He then makes a U-turn and heads back towards Ashburton before turning onto Elizabeth Ave, Rakaia.

At 7.17pm, the car is seen exiting Rolleston St and travelling north on SH1. He turns onto Main Rakaia Rd and pulls over, dumping Duckmanton's body near the roadside before setting it alight.

SUPPLIED Gambian-born Christchurch butcher Sainey Marong pictured after his arrest on May 26, 2016.

"I couldn't resist myself. I struggled to stop it after the ignition," he told the court during his trial.

Emergency services were first notified that a body had been found about 7.40pm.

Footage of Duckmanton's final movements before she got into Marong's car have also been released.

JOHN KIRK-ANDERSON/STUFF Duckmanton was found dead by Rakaia River in Canterbury on May 15, 2016.

Shortly after 9pm on May 14, Marong's Audi is seen turning off Manchester St, where Duckmanton was working, onto Peterborough St and parking out of sight.

Seconds later Duckmanton, wearing a black hoodie, white top and white shorts, walks past a private camera at St Luke's Close apartments in the direction of Marong's car.

CCTV footage from 9.36pm shows Marong withdrawing $300 from an ASB ATM on Riccarton Rd at the same time Duckmanton calls her boyfriend telling him her client wanted to take her home and would pay $300. The transaction would later prove pivotal in helping police identify Marong as the killer.

JOHN KIRK-ANDERSON/STUFF Sainey Marong was sentenced in the High Court at Christchurch on Friday.

'HARROWING CASE'

Duckmanton's mum, Tracy, yelled "yes, yes," and thanked the jury on behalf of her daughter and the family when they returned the guilty verdict after only 50 minutes on Friday.

Detective Inspector Darryl Sweeney said it had been a "harrowing case for everyone involved" and the guilty verdict was the right result.

FACEBOOK Sainey Marong pictured wearing the same beanie and hoodie he was wearing when he killed Duckmanton.

"The result won't provide closure or solace for Renee's family, but it is important for everyone that they have answers and that the offender has been held to account."

In court Marong claimed he was suffering from a "disease of the mind" when he killed Duckmanton.

Psychiatrist Dr Erik Monasterio​ said Marong's proposed defence was "farcical".

SUPPLIED Duckmanton, right, with her mother, Tracy.

"In my opinion this proposition is preposterous. I have no evidence of what's being proposed here."

Crown prosecutor Pip Currie said the insanity defence was "clutching at straws".

"[This is] a man who has nothing else to put forward in way of defence. He's fabricating his evidence as to what was going on in his mind."