A vehicle belonging to missing woman Jessica Boyce has been found at Lake Chalice.
Boyce, 27, has not been seen since last Tuesday. However, her vehicle has been located at Lake Chalice, in Mt Richmond Forest.
Constable Al Hendrickson said police are appealing for information regarding her whereabouts.
"Her family are concerned for her wellbeing," he said.
"We are seeking information on Jess' movements in the weeks leading up to her disappearance, particularly Jess' actions and activities throughout the Blenheim and Renwick areas.
"We wish to speak to anyone who has been up the Lake Chalice road since it recently re-opened."
Police earlier sought sightings of Boyce's red Holden Rodeo ute between Tuesday and Friday, March 22.
Boyce is reported to have contacts in Blenheim, Nelson and Christchurch.
A public appeal on social media has asked people to look around rivers, bush areas, walking tracks and camp grounds in these regions.
Searches for Boyce are being carried out by Land Search and Rescue (LandSAR), including by helicopter and dog units.
As the search enters its seventh day, an active front is moving up the South Island, with a heavy rain watch in place for northwest Nelson and the Richmond Ranges on Wednesday morning.
A strong wind watch is also in place for Marlborough from 10am this morning until tomorrow morning.
Anybody with information on Boyce's whereabouts should contact Blenheim Police on 03 578 5279.