The helicopter was called to the area after an older model emergency beacon went off.

The radio signal the beacon sent out was picked up by planes flying over the site and the ambulance helicopter was called to the scene.

Unable to find where the signal was coming from, the pilot landed the helicopter in a reserve in Twynam Place.

Wayne Hodge, who lives nearby, told the Champion more than 100 people gathered around the helicopter when it landed.

``We couldn't believe it,'' he said. ``They still couldn't find the beacon when they landed. They were looking for about two hours.

``It was a bit of a waste of time for them because they could have been saving people at the time. And they told me it costs about $4000 an hour to run the helicopter, so that time could have been better spent.''

Green Valley Police Constable Tim Reynolds was called out to the scene by residents.

``The beacon was eventually traced to the Prestons Grand Bazaar markets,'' Constable Reynolds said. ``It was probably an old beacon that had just been bumped by someone or dropped. It stopped sending out the signal after a while.

``Emergency services need to check out any alerts like this in case they're valid, even though this is a very old-fashioned sort of signal.

``They're all linked to satellites now.

``Ambulance officers told us they don't get call-outs about such signals very often only about once a month.''