Dave Sonik Jordan (right) and Raymond Harper with the cannon retrieved from the river.

Dave Sonik Jordan, 46, and Raymond Harper, 73, latched onto the artillery piece while magnet fishing - which is where people use magnets to pull treasure out of water.

It took the pair, who have been fishing together for ten years, over an hour to get the 3ft (91cm) object out of the River Don in Sheffield. The cannon's origins are currently unknown but Raymond and Dave believe it could be anything between 200 to 600 years old.

YouTuber Dave has said he thinks the artillery piece could be the first one to be discovered in a river in the UK and said he was 'elated' to have found it.

He said: "I've never seen anything like this before. We always come across weird and wonderful stuff but this cannon takes the cake. When we were pulling it out, we just looked at each other and said 'it's a frigging cannon.' "I just thought 'cannon - oh my god' and we were really elated as it's the holy grail of finds.

"A few people talk about it and say it's on their bucket lists to find one and we've just come along and found it. We never thought we would find something as amazing as that when we started our journey cleaning the environment.

"It might be the first cannon to be discovered in-land, in the UK or in the world. I'll never find a cannon again - this is once in a lifetime."

Dave took the cannon back to his home in Northampton and is planning to contact the British Museum's Portable Antiquities Scheme to report the object. But although he is estimating it could be from '200 to 600 years old', he doesn't know for sure how old it is but is interested in finding out the cannon's history.

Dave said: "It's still covered in rust at the moment but I don't want to clean it up just yet. It could be anything from 200 years old, which would be from the Napoleon time period or it could be from the civil war. It also could be from when the Sheffield castle was demolished or it could have been brought back from a war from a merchants ship.

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"It could have been anything but until it gets cleaned up a little bit and we can see some markings on it, then we haven't got a clue. We know it's old because when was the last time a cannon was used? It's just whether it's 200 years old or more 500 to 600 years old, we just don't know.

"But it could also be something to do with the manufacturing side of Sheffield but we haven't got the foggiest."

Dave started magnet fishing ten years ago and enjoys going to different rivers in the UK and cleaning rubbish out of them.

He said: "We go out and clean the environment and rivers for around ten hours a week. Anyone could have got the cannon out of the water if they knew it was there but we spend so much time sorting out rubbish and that's how we come across stuff.

"It's not just as easy as walking up to somewhere and finding the cannon. It's pure luck and you never know what's down there."

In November last year, Dave helped reunite retired police officer Geoffrey Barron with his exemplary service medal after it was stolen from his home. Dave found the medal after he was scouting for treasure in the River Nene, Northampton.