Emma Beattie has been missing since late last year.

Police are focusing on the area around a north Canterbury river in their search for a missing woman.

Search and rescue teams have been called in an attempt to locate 20-year-old Emma Beattie from Rangiora.

She was last seen at her Fernside home around 11pm on Friday, but police believe she may have been near the Ashley River on Saturday.

They asked anyone who may have seen Beattie to contact police immediately as there are concerns for her wellbeing.

Emma has long blonde hair and was believed to be wearing orange-and-black Nike shoes.

She may also be carrying a small brown drawstring rucksack with cream coloured rope straps.