Chinese national Tingjun Cao, 53, is on trial for killing Bao on 19 July last year, the day she went missing.
The Crown case is that Cao murdered Bao after arranging to meet her at a home for sale in Hornby.
Cao was arrested at Christchurch Airport just days after Bao's disappearance, on 22 July.
On Tuesday, the trial heard from detective Geoff Reid who told the court he examined items that were taken from Cao after he was arrested.
He found Air New Zealand paperwork in a brown satchel.
"It showed Mr Cao had purchased a ticket from Christchurch to Auckland then Auckland to Shanghai with a total cost being just over $700. The booked flight was scheduled to leave Christchurch on Sunday 23 July 2023," Reid said.
Reid said the receipt showed the ticket was purchased the afternoon of 22 July.
She ran the registration, and the vehicle showed an alert for possibly being linked to a missing person.
"The [driver] was of Asian descent. He looked to be in his 50s and he was wearing a long black trench coat. I said hello to the male and I asked for his driver's licence. He did not speak one word of English to me, he continued to shrug his shoulders to me and hold his hands in the air. He began to walk towards me, I saw he was holding a cellphone that had a large black case."
Howe said as she looked at the phone she saw that the man had scratches on his hands.
"I believe they were quite fresh as there was blood coming from some of the scratches," Howe said.
"I also observed some mud on the tyres and rear bump of the vehicle as I was looking at it."
Constable Clayton Davison, who arrived at the scene to assist, told the court he asked the man if his licence was in a brown bag he found in the car.
"He said 'yes yes yes' and was nodding his head while smiling. I took the bag directly to the male where he produced his passport alongside his full New Zealand driver's licence which was a paper copy of the licence.
"I took a photo of the passport, I saw his passport, I saw the male's name was Tingjun Cao. Once the identification was confirmed we finished at the vehicle stop and continued on with my regular duties," Davison said.
Cao earlier sacked his defence, choosing to represent himself.
During cross-examination, Cao asked Davison if there were any suspicious items found in his boot. Davison said there were not.
On Monday, a funeral service was held in Christchurch for Bao.
The trial continues.
