Police divers will join the search for missing Torbay woman Pat Wearn, three days after she went missing.
The 73-year-old, who has Alzheimer's, went for a walk on Monday afternoon and alarms were raised when she didn't return home.
Members of the Police National Dive Squad are on their way from Wellington to Auckland to join the large-scale search operation, police spokeswoman Beth Bates said on Wednesday.
They're expected to target a number of waterways and ponds near Mrs Wearn's home.
She went shopping with her husband on Monday morning and left home again about midday to go on a regular walk along Caversham Drive, Lingham Crescent, Glamorgan Drive, Kate Sheppard Avenue and back to Caversham Drive.
She was wearing blue 3/4 length trousers and a patterned top.
It's the first time Mrs Wearn has disappeared, prompting concern for police who now hold grave fears for her safety.
"Police are working with Mrs Wearn's family and are doing everything possible to support them at this difficult time," Ms Bates said.
"They have expressed their thanks and gratitude to the many members of the public who have given up their time to help look for Mrs Wearn."
Members of the public have flooded the Browns Bay police station with offers to help but officers say the search will continue with specially trained search and rescue members.
"Our biggest request of the public is that they check their sheds, garages, and places where Mrs Wearn could have gone to seek shelter or rest," Senor Sergeant Adrian Kerin said on Tuesday.