Sailors from the Royal Navy bomb squad – based at Horsea Island – were mobilised on Sunday afternoon.
It followed the discovery of the suspected device on Lancing Beach, near Worthing in West Sussex.
The bomb squad was joined by the Shoreham coastguard as they investigated the suspected mortar.
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Images of Royal Navy Divers from the Southern dive unit at work. They demonstraited the kit they would use for underwater bomb disposal. This imagery is to be used to support the news stories of any ordinance found by the dredger in Portsmouth Harbour as it is being cleared for the arrival of the Queen Elizabeth Aircraft Carrier.
A spokesman for the Royal Navy said: ‘Members of the Royal Navy Southern Diving Unit 2, based in Portsmouth, were called to Lancing beach in West Sussex where after examination they removed an item, which was found to be non-explosive.'