Tingjun Cao is accused of murdering Yanfei Bao in 2023. Photo: RNZ / Nate McKinnon
The man charged with the murder of Christchurch real estate agent Yanfei Bao has accused police of falsifying evidence.
Chinese national Tingjun Cao, 53, is representing himself in his High Court trial at Christchurch after sacking his defence lawyers last week.
Bao, 44, vanished on 19 July 2023, and her remains were found in a shallow grave in farmland on the outskirts of Christchurch more than a year later.
Cao is charged with her murder.
The Crown is arguing that Cao murdered Bao on the day she vanished after arranging to meet her at a home for sale in Hornby.
As the trial entered a fourth week on Monday, the murder accused continued to handle his defence case with his former lawyers Colin Eason and Joshua Macleod remaining as standby counsel.
During cross-examination of both police digital forensic analyst Joshua Locke and later Detective Constable Andrew Calder, Justice Lisa Preston intervened several times to caution Cao.
Cao's questions, asked through a team of interpreters, were regularly deemed by the judge to be irrelevant, beyond the core responsibilities of the witness, or had already been asked.
Locke examined the cell phones of both Bao and the murder accused.
Yanfei Bao, 44, vanished on 19 July 2023. Photo: Supplied
After asking several questions of the witness, including a significant portion as to whether a person could make a phone call and send a text message simultaneously, Cao put it to Locke that the data extracted from his phone was "all false" and that he "seriously questioned it".
"I suppose I'd add that the data that I've made my analysis using, to my knowledge, has been disclosed to Mr Cao and his legal advisors and all that data is available for them to verify if they wish to," Locke replied.
Detective Constable Andrew Calder, who worked on the investigation team that was responsible for retrieving "items of interest" around the Lake Terrace Rd area in Burwood following Bao's disappearance, also took the stand.
The court heard how the officer located an empty white bag near the river bank.
Other items including a wet wipe, a heavy metal pole, and two vehicle carpet liners were subsequently found by police search teams.
Calder was also in charge of a scene examination at Cao's Bryndwr property following his arrest, and for seizing items on the property.
During cross-examination, Cao repeatedly asked about how these items were analysed despite repeated explanations that this was the responsibility of other investigators.
"The defendant needs to remember that I did not conduct every role in relation to this investigation," Calder said.
"I can only give evidence relevant to what is in my statement."
Cao ultimately concluded his questions by stating that Calder "in every line, and in every paragraph, made a false statement".
Calder calmly replied: "that's not true".
Detective Constable Grace Schurgers and Constable Duncan Fosbender also delivered brief testimonies.
Fellow police detective Geoff Reid, who was responsible for court applications pertaining to search warrants, telecommunication and financial data in the investigation, will resume his evidence on Tuesday.
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