Officers searching for her ex-husband confirmed a 28-year-old man had been arrested on Saturday. Superintendent Alan Chung earlier told the news agency AFP that three others had been arrested and would face murder charges.
Chung said authorities believed the 28-year-old model had financial disputes involving tens of millions of Hong Kong dollars.
He also revealed that “some people” were unhappy with how Choi had handled her financial assets.
Officers discovered two legs in a refrigerator on Friday after breaking into a house in the village of Lung Mei Village in Tai Po. They also found the victim’s identity card, credit cards and other items, Chung said.
“Tools that are used to dismember human bodies were found in the flat,” he said.
Human tissue was also found, Chung said, but police were not able to locate the victim’s other body parts.
Chung said the victim was 28 years old and a model whose surname was “Choi”. He did not disclose her full identity but the South China Morning Post and other media have identified her as model Abby Choi.
The model, who was reportedly last seen on Tuesday, was the cover star of the latest edition of L’Officiel Monaco magazine.
Ms Choi had more than 80,000 followers on Instagram.
Additional reporting by agencies