Police say missing woman Bridget Simmonds may have been offered a ride back to her home address on the day she was last seen.
The 42-year-old was last seen when she was dropped off by family at Countdown Regent in Whangārei on February 23.
She was reported missing on March 6 and police immediately began making inquiries to help find her.
Since the start of March, police have made public appeals for information regarding at least five people who are still missing.
Detective Constable Joseph Reuben said Simmonds had not been in contact with her family since she went missing.
"Bridget hasn't been in contact with her mother or family since she disappeared, which they say is very unusual," he said.
"They are growing increasingly worried about her."
She has a large distinctive tattoo on her upper left arm of a fairy and was last seen wearing a dark coloured singlet and black jeans.
She had three large black and grey backpacks with her.
Police believe she may have taken a taxi or may have been offered a ride back to her home address that day, Reuben said.
"Anyone who may have picked her up in their car or taxi or taken her anywhere is urged to contact police," he said.
"Police, and her mother and family, just want to make sure she is safe."
Police are also interested in hearing from anyone who may have been in contact with her in the weeks leading up to her disappearance.
Anyone with information as to her whereabouts can contact Reuben on 021 191 5901 or Crimestoppers anonymously on 0800 555 111.
Since the start of March, police have made public appeals for information regarding at least five people who are still missing, including Simmonds.
Counties Manukau police acting senior sergeant Jade Gardiner has asked the public to report any sightings of Chunji Gao, also known as Gary Gao.
The 25-year-old was reported missing on March 25, and police have been making inquiries to find him since.
"His family have not seen him for the past year," Gardiner said.
"Mr Gao is autistic and has been known to run away in the past."
Police and his family are worried for his safety and are asking for anyone with any information about his whereabouts to contact them immediately, she said.
"We are continuing to make enquiries to locate Mr Gao and find him safely, and any assistance from the community would be appreciated."
Anyone with information can contact police on (09) 571 2800 or Crimestoppers on 0800 555 111.
Guoquan Wu, also known as Laurence Wu, was last seen on Sainsbury Rd in the Auckland suburb of St Lukes on March 10.
His Hyundai Santa Fe was found at Piha Beach car park two days later.
Wu's family hired a helicopter to help scour the west coast in the search for the 22-year-old University of Auckland student.
Police are still making inquiries.
Police have appealed to the public for any information regarding sightings of Eleanor Wright who was reported missing on March 27.
Both her family and police have concerns for her welfare and ask that anyone who may have seen her to contact police immediately.
Information can be reported to Auckland City Police on (09) 302 6400, quoting Police file number 190329/8447.
Boyce, 27, has not been seen since March 19.
However, her red ute was found at Lake Chalice, in Mt Richmond Forest.
Police suspended the search for her on March 28 but said they would continue to follow up any further information that comes to hand.