An umbrella designed to look like a rifle sparked a police scare at Chadstone Shopping Centre this afternoon when a security guard reported a gunman was on the loose.

A police helicopter and about 10 police officers raced to the shopping centre but soon discovered the man believed to be carrying a firearm was in fact brandishing an umbrella bought from clothing store Dangerfield.

An umbrella similar to the one sold at Chadstone.

Sergeant Tony Marasco from Malvern police station said the umbrella looked realistic enough for a security guard to call police and report a man had a firearm strapped to his back.

But police were soon informed that the gun was in fact a novelty umbrella.