She was last seen just before dusk on Sunday, September 20, and failed to show up at work at a beekeeping business just 400m from her house the following morning.
Ewings had previously lived at accommodation at the beekeeping operation – mainly used by seasonal workers and which includes a caravan - but had moved to her own place about a month ago.
On the day she was last seen, she visited neighbours at around midday.
They told the Herald she appeared "good as gold" and "happy" during the half-hour visit.
An official missing persons search was launched last Monday.
Ewings' house was reportedly found locked, and her car, wallet and bank cards left behind. None of her personal belongings were missing.
Her cellphone was missing, though – and was tracked to within 100m of her home, the Herald earlier revealed.
After widespread searches, it was later found, Senior Sergeant Peter Payne confirmed this week, along with other items of interest. The phone was now being analysed.
"Police continue to follow up on and assess information received about where Melissa may be, and her movements, and maintain an open mind as to what has happened," a police statement released this afternoon says.
"Anyone who locates anything that may be of interest in relation to this case is urged to contact Blenheim Police on 105."
Police search teams have gone through all of the local properties and spoken to the residents, the Herald understands, along with Search and Rescue teams scouring the nearby Clarence River which has been swollen and muddy since her disappearance. Coastline checks have also been done, and helicopters have been looking from the skies.
They have searched daily over an extensive area around Clarence and the Clarence River.
• Anyone with information about Ewings should call police on the non-emergency number 105, quoting file number 200922/5064.