Police were on an information blitz all yesterday, trying to get the image of Alyssa in as many people's memories as possible.
Signs about Alyssa had gone up through towns from Auckland to Wellington with electronic motorway signs broadcasting appeals.
The Westpac helicopter was joined by 30 Land Search and Rescue volunteers.
Officers knocked on doors along Glengarry and Pisces Rds, Glen Eden, and motorists driving along nearby Glengarry Rd were shown photographs of the missing pair.
Police confirmed Skye Mason had mental health problems and Detective Inspector Stan Brown warned she may have had a relapse.
