The grenades were discovered at Harry Bussell’s Carboor alpine dorper sheep stud by a pest exterminator assessing white-ant damage in a shed.

One of the grenades was in the back of the shed, the other was on the ground.

“They would have been from my grandfather — he was in the First World War, he was also in the Volunteer Defence Corps in the Second World War and they were 1940s ordinance,” Mr Bussell said.

“One was possibly a bit older but it was hard to tell.”

Mr Bussell said his grandfather, who died in 1959, bought the property after World War II.

The shed where the grenades were found is near the original house.

“It was a bit of a surprise; my father didn’t know about it and he’s passed on, he never mentioned it to me,” he said.

Mr Bussell said he had been in the shed many times but the grenades clearly were not “terribly visible”.

Police were called then alerted army specialists once the grenades had been identified.

One of the pieces, believed to date from between the world wars, was in a rusty state and was considered too risky to remove from the property.

Explosives were used to detonate that grenade while the army personnel took the other grenade, which was stamped 1940, to Latchford Barracks at Bonegilla.

It will then be transferred to Wirlinga.

“One was the size of a chook’s egg. The later model was a much bigger bit of gear, it was tennis-ball size,” Mr Bussell said.

Victoria Police spokesman Glen Atwell said it was essential for anyone who discovered a grenade or other explosive device to leave it alone and contact authorities.

“If you happen to come across any explosive device, antiquated or not, the most important thing to do is to alert police immediately,” he said.

“Don’t touch the device and remain a safe distance away until authorities arrive.”