One of the last people to talk to a Christchurch real estate agent before she went missing has described the extremely hard week waiting for any news about her friend.
The police national dive squad is expected to begin scouring Christchurch's Halswell River on Wednesday morning as the desperate search for Yanfei Bao, 44, continues.
Bao has officially been missing for a week, having last been seen doorknocking in the suburb of Wigram last Wednesday.
On the day she went missing, Bao also phoned her friend Jin for work-related advice.
Jin told AM it was Thursday morning when she realised something was wrong.
"Last week's been extremely hard for all of us."
Jin said she'd known Bao for five years.
She was "so shocked" when she learned of her disappearance, she said.
"She's… a person with a purpose in life and she's so caring as well," said Jin.
Bao has a 9-year-old daughter, who Jin said was "not well".
As well as the Halswell River, officers will on Wednesday comb the nearby area of Greenpark - about 17km from the Wigram where Bao went missing while doorknocking last Wednesday.
On Sunday, a 52-year-old man was arrested and charged with kidnapping Bao - with further charges and arrests not being ruled out.
Officers on Tuesday zeroed in on a property on Christchurch's Trevor St, also not far from where Bao went missing. Police would remain at that address on Wednesday, Det Insp Nicola Reeves said.
Timeline
Bao, a mother-of-one, recently joined Harcourts as a real estate agent and has extensive experience in sales.
She was last seen on Vickerys Rd in Wigram at about 10:30am last Wednesday. Her car was left parked on Iroquois Pl.
Police and Bao's family have said her disappearance is very out of character and there are deep concerns for her safety.
Officers earlier located one of her cell phones nearly 7km from where she was last seen. Investigators found it in the grass berm along the Southern Motorway thanks to assistance from the public.
Investigators have now searched three properties as part of the probe, dubbed 'Operation Helo'.
