Rescue teams are concerned about trampers missing on the Milford Track.

At 6pm yesterday, three Australian trampers activated an emergency locator beacon.

Rescue Coordination centre spokesman Micheal Flyger says bad weather meant that a helicopter was unable to get to the site, near Mintons Hutt last night.

A helicopter from Te Anau is currently searching the area for the group.

Heavy rain and bad weather is forecast for the area over the next few days.