A scene examination is underway after a person died in an incident in central Blenheim early this morning.
One person died and two were seriously injured outside a night club on Market Street. Police were called to the area just before 3am.
Marlborough Mayor John Leggett says locals are shocked and saddened by the incident.
Leggett is asking people to help police if possible, and not get in the way of the investigation.
"Keep away from the site," he said.
"I think it's a time that we all have to get in behind our police and emergency services and do our part, if we are able to help in any way."
Leggett said Blenheim has recently been declared one of the safest places in New Zealand, in the Crime and Victim Survey.
Marlborough Area Commander Inspector Simon Feltham said the scene has been cordoned off and there will be an extra police presence in the area to ensure the community's safety.
Witnesses or anyone with footage of the incident is being asked to contact police.