VIDEO: Bomb disposal squad detonates grenade outside Northampton village

Precision engineer Tim Whiting, from Brixworth, found the item last night when he was dangling a magnet into the river along Merry Tom Lane between Chapel Brampton and Brixworth.

The amateur metal detecting enthusiast was hoping to unearth some old coins or unusual artefacts when he pulled it out the river.

A bomb disposal team from Nottingham attended the lane this morning to carry out a controlled explosion and the site has now been cleared.

"I was pretty surprised," said 33-year-old Mr Whiting abut finding the relic last night.

He initially held the item in his hands when he first pulled it out the river before taking photos of it and posting the snaps on an internet forum.

After fellow amateur historians confirmed the find was most likely an unexploded device, Mr Whiting gingerly laid it down on the riverbank and called 999.

Police had to remain at the scene overnight as a precaution.

But Mr Whiting said it was sheer luck that no one had stepped on the relic before.

"I used to swim in there as a child," he said.