The wallabies, which have become a widespread pest in South Canterbury, have so far been restricted to a containment area.
But now Environment Southland is investigating the possibility that wild wallabies have spread to their region. High country farmers now say the wallaby population is well over one hundred thousand and spreading well beyond that area.
It comes after reports last month, that Southland Regional Council has been left stumped, after a dead wallaby was found near Gore - far from South Canterbury where they usually roam.
Bill Nagle, who is a member of the Invasive Species Specialist Group, talks to Jesse Mulligan.