The police helicopter was mobilised over Trowbridge town centre around noon today after reports of a man carrying a shotgun.
A passenger in a car phoned police after seeing what they believed to a man carrying a shotgun on Wicker Hill and walking towards the town centre at about 11.25am.
CCTV searches and foot patrols could find no evidence of the man and after the helicopter was mobilised, police scaled down the search.
A Wiltshire Police spokesperson said: "Its possible the caller was mistaken but we'd always ask anyone in that situation to do the right thing and get in touch by calling 999.
"We are grateful for him for getting in touch and will continue the search."