A man murdered his parents, chopped up their bodies and cooked them with rice “like barbecued pork” to hide the evidence, a court in Hong Kong has heard.

Henry Chau Hoi-leung, 30, and his accomplice, 36-year-old Tse Chun-kei are accused of planning the gruesome killing for more than three months, using the time to buy knives, refrigerators, microwaves and a rice cooker.

His parents, Chau Wing-ki, 65, and Siu Yuet-yee, 62, went missing in March last year and their heads and organs were found stuffed into two fridges in a bloodstained apartment two weeks later.

Their dismembered bodies had been salted and packed into lunchboxes, the South China Morning Post reported.

Hong Kong’s Court of First Instance heard that Chau told police after his arrest that he and Tse killed on 1 March because “they felt ready”, the court heard.

The couple were last seen on CCTV walking into a building in Tai Kok Tsui with Henry Chau on 1 March and he reported them missing two weeks later, claiming they had gone to mainland China “to have fun”.

The police arrested him and Tse the next day, discovering the dismembered bodies in the flat along with notes and receipts suggesting pair had started planning the killings in November 2012.

Michael Arthur, a lawyer for the prosecution, said: “Their crime was greatly premeditated. Their planning was extensive.”

After his arrest, Henry Chau told police that he and Tse killed his parents, but that it was Tse who dismembered the bodies.

He said he chose to kill his parents because his “emotional connection with them had broken down”, the South China Morning Post reported.

Henry Chau and Tse both denied two counts of murder in court yesterday but admitted two counts of preventing lawful burial.

The prosecution did not except Henry Chau’s guilty plea to manslaughter on the basis of diminished responsibility due to his “abnormality of mind”.