Concern is increasing for missing Marlborough woman Melissa Ewings

Police investigating her disappearance say the 31-year-old hasn't been seen for nearly a fortnight, despite an extensive search operation.

Ms Ewing's family say it's out of character for the keen adventurer not to keep in touch with them.

A Police spokesperson says they are continuing to follow up on and assess information received about where Ms Ewing may be and her movements.

Anyone with relevant information is asked to call Blenheim Police on 10-5 .