HONG KONG (AFP) - British banker Rurik Jutting calmly described to police graphic photos of an Indonesian woman he had killed at his luxury apartment in Hong Kong, according to video footage shown in court Thursday (Oct 27).

The 31-year-old Cambridge graduate and former securities trader for Bank of America-Merrill Lynch has pleaded "not guilty" to two murder charges, on the grounds of diminished responsibility.

He pleaded guilty to manslaughter, which was rejected by the prosecution.

Since the trial started Monday, jurors have viewed harrowing iPhone footage of Jutting torturing his first victim, Sumarti Ningsih, 23, for three days before he killed her by cutting her neck with a serrated knife at his flat two years ago.

Days later, he killed Seneng Mujiasih, 26, cutting her throat, also at his flat. Both women were found dead at his apartment on Nov 1, 2014, Ningsih's body stuffed in a suitcase.

On Thursday, the final day of prosecution evidence in the trial, the court viewed video footage of police interviews with Jutting as he talks through photos of Ningsih taken by him on his iPhone.

When shown the pictures by police he carefully described their content.

"She is currently tied up by me... she is being restrained here against her will. She absolutely did not consent," Jutting told officers when asked about one of the photos.

He adds: "This photo was taken during around three days that she was captive against her will in my flat." Jutting told police in the interview that he was "in a state of extreme sexual aggression" during that time.

In other clips from the police interviews in which he is describing photos from his iPhone, Jutting says the images showed Ningsih bound and gagged, and she had marks on her body from being beaten with a belt by him.

When shown a photo of his bloodstained bathroom he described to police in the video how he cut her throat there, tied her body with a rope, then wrapped her in a plastic bag, a bed sheet and a throw before putting her in a suitcase.

Jutting told police interviewers that after he attacked his second victim, Mujiasih, he collapsed "physically exhausted".

"She was I think still alive and still moving. I collapsed outside on the balcony. When I went back in she wasn't moving. I didn't specifically check whether she was dead or alive," he said in the interview.

Jutting said he had considered jumping from the balcony and at one point he climbed over to a neighbour's balcony, waving a kitchen knife and carrying vodka, cocaine and Red Bull.

Jutting then went back inside where he rang police.

He told officers in the interview tapes that he had bought "10 packets" of cocaine daily for the three weeks before Nov 1, at HK$1,000 (S$180) per bag.

"I had ingested it primarily by snorting it," Jutting told police in the video.

Wearing a light-blue shirt, Jutting remained impassive in court, sometimes looking at the video footage and sometimes scanning the room.

Jurors were also shown the knife he used to kill Mujiasih and were taken through some of the graphic photos one by one by the prosecution.

The court heard Tuesday that Jutting was "deeply addicted" to cocaine and also drank heavily.

Jutting faces a life sentence if convicted of the murders. The defence is due to open its case on Monday.

The killings shone a spotlight on the seedy underbelly of the finance hub. Jutting's flat lay streets away from one of the city's red light districts.

Indonesian migrant organisations in Hong Kong have called for justice for the women, and compensation for their families.