Michaela Leger, 29, from Ōtaki, is yet to be found despite a search by air, land and sea.
She was last seen on Saturday night when she allegedly stole a kayak from a Raumati property and entered the water at Raumati Beach around 8pm.
Detective Senior Sergeant Peter Middlemiss said in an update today police have made extensive inquiries.
“We now believe the kayak had only one seat and want to hear from anyone who saw a single-seater kayak in the days since Saturday 21 October but did not report it.
“A team of investigators is continuing to follow any lead that may lead us to Michaela.”
Middlemiss said police are concerned for Leger’s safety and are providing support to her whānau.
Police thanked those who had been involved in the search so far including LandSar, Coastguard, Surf Lifesaving NZ, the Department of Conservation, and the Royal New Zealand Airforce.
Anyone with information can contact police via 105 and quote file number 231022/0452.
Earlier this week, Kāpiti Coast District Council confirmed a dog photographed alongside the missing Ōtaki woman was being looked after.
The dog was in the hands of its Animal Management team, but the council could not confirm who it belonged to on Tuesday.