Lois Tolley killing: Police release CCTV of four men leaving her flat

New CCTV footage has been released as police continue to investigate the killing of Upper Hutt woman Lois Tolley.

Ms Tolley died on December 9 last year in what police have described as an "execution-style killing", after she was stabbed before being shot at point-blank range.

Four men had walked into her flat that night and police have now released CCTV footage of them leaving, including one man who appeared to be visibly distressed.

His reaction was overheard by neighbours and police said he was calling out, "What have we done?" and swearing.

Police have also released photos of two vehicles of interest, a silver Mazda 6 and a silver Nissan Stagea, which are believed to be linked to the slaying.

Lois Tolley killing cars sought (NZ Police)
(NZ Police / supplied)

Two other cars seen in the area, a blue sedan and a blue hatchback, are also being sought by police. One is believed to be a Sudan WRX.

Detective Senior Sergeant Glen Barnett says one of the men is bound to have spoken to someone else about the attack and urges anyone with information to come forward.

"Your calls will be treated in confidence, and any information - no matter how small - will be welcomed by in the investigating team," he said.

Anyone with information is asked to contact the Operation Archer team on (04) 527 2300, or anonymously via Crimestoppers on 0800 555 111.