A suspected World War Two Japanese hand grenade and spent ammunition have been found by a family on a beach in Western Australia’s Kimberley region.

The items were found by a Broome couple who were walking with their children and dog at a beach between Port and Gantheume Point last Tuesday.

Senior Sergeant Brendon Barwick said the family located ammunition casings in tidal pools and started collecting them, and soon found the suspected grenade.

“It is possible that recent heavy rain and rough weather conditions unearthed the items,” he said.

“The couple took the casings and object home, and became suspicious of it and called police.”

Military personnel identified the object as a 1941 Japanese hand grenade, police said.

It is packed in sand awaiting a military ordnance team, who will arrive in Broome later this week to dispose of it.