Mum of Auckland teen Mia Stewart thanks public for support as 15-year-old remains missing

The mum of missing North Shore teenager Mia Stewart, has thanked the public for their support as police continue to search for the 15-year-old in Auckland.

Tracey Stewart posted the thank you message on Facebook this evening as a comment on an earlier post - updating the search for her daughter - who was last seen on Friday night.

"Thank you everyone for your love and concern Mia is not yet found and home with us xxx," the comment reads.

This morning police confirmed to 1 NEWS they were "investigating a missing person's report relating to Mia".

Detective Senior Sergent Nadene Richmond said a team based in Orewa were working on finding Mia.

"Police are working through enquiries at this stage and we are following up reported sightings of Mia," Ms Richmond said.

An update from police tonight says they're still searching for Mia.

Where is missing Mia?

Late yesterday, Mia's mother Tracey Stewart posted about being "absolutely sick with worry" on Facebook.

Mia was last seen on Friday December 14 around the North Shore and Hibiscus Coast area.

Mother Tracey said the teenager's phone hadn't been used and she hasn't been active online since early Saturday.

"If anybody knows anything or has seen her at all this weekend please contact ..the police."

She added that Mia had been battling anxiety and was with people she didn't know very well on the day she went missing.

Mia Stewart Source: Facebook