A University of Hong Kong professor accused of murdering his wife aroused police suspicions after he gave conflicting accounts about the contents of a heavy box he moved from his flat following his spouse’s disappearance two years ago.

The High Court heard on Wednesday that police officers spotted Cheung Kie-chung transporting a wooden box to his office using a hired van on August 22, 2018, five days after he allegedly killed 53-year-old Chan Wai-man.

The 56-year-old associate professor at HKU’s engineering faculty initially said the home-made box contained items for beach activities during the university’s orientation camp, but later told police it stored metal parts for a robotics competition.

That discrepancy prompted police to move the missing person case of Chan to the Hong Kong Island regional crime unit, which eventually led to the discovery of her body inside a box in Cheung’s office and his arrest on August 28.

The court was told police had been unaware of Cheung’s role in the case when officers went to his flat at the university’s Wei Lun Hall for inquiries in the early hours of August 21, soon after he and his daughter Nancy reported Chan missing.

The following morning, officers went to conduct further investigations at the flat, only to find Cheung at the hall’s car park moving a bulky wooden box, covered with a blue cloth with a cooking stove and microwave oven on top.

Constable Cheung Ka-lun, who witnessed the incident, said the box appeared heavy, as the professor pushed it on a trolley with great difficulty, panting and covered in sweat.

Asked about the box’s contents, the professor hesitated for a few seconds before saying it contained beach equipment.

That answer did not ring any alarm bells with the constable until he visited Cheung’s home again two days later, when he found some items in the flat missing and the cooking stove back in its original place.

He invited Cheung for an interview at Wan Chai police headquarters that afternoon, where the defendant claimed the box had stored electrical equipment and aluminium bars for use in a robotics competition.

The officer told the court: “I found that he looked very calm and indifferent, so much so that he did not seem to care about the passing of the deceased.”

On August 26, Station Sergeant Cheung Siu-yin called the professor to the police headquarters for an interview and then asked for another visit to his home, where he asked the defendant: “Where did you hide your wife?”

The professor was said to have remained silent for about 10 seconds, before replying: “Why do you suspect me?”

The sergeant said that after the professor led officers to a laundry room at the hall, he suddenly leaned against the edge of a wall in an attempt to climb over and jump from the building. He later found the professor had sent a WhatsApp message to his family, saying in English: “I wanna jumping.”

After Cheung calmed down, he led police to his office, where officers found an unpleasant smell. The sergeant said he could not locate the source of the smell and did not probe further.

But when he and his team returned on August 28, they found the odour had permeated the whole floor. The professor, who was sitting in his office, claimed the smell could be from a dead rat.

The sergeant said he noticed Cheung became more anxious as he pressed him with questions such as “Is your wife dead or alive?” and “Where is your wife?”.

Officers found the wooden box under a fish tank after a two-hour search. The sergeant asked Cheung what was inside the box, to which the professor replied: “You have found the box already. You know what’s inside without me telling you.”

Chan’s body was later found in a suitcase stuffed inside the box.

The trial continues before Madam Justice Anthea Pang Po-kam.