Reports of an armed man roaming through Cassiobury Park this afternoon turned out to be a false alarm, because the "rifle" has was carrying was just a toy.
At least three police cars and a helicopter were called to the central Watford park shortly before 12.30pm.
Officers raced to the scene after a member of the public reported seeing a man armed with a rifle, and police cars were left parked at the Rickmansworth Road entrance.
A police helicopter circled overhead, trying to spot the man, however, claims that he was carrying a gun turned out to be slightly wide of the mark.
Sarah Spence, a police spokesman said: "We got a call at 12.25pm from a member of the public who saw a man possibly walking about with what they believed to be a rifle.
"We attended and made numerous inquiries and we are now quite confident it was a toy."