If you fancy yourself as a cut-price Indiana Jones, it could be the hobby for you.

All you need is a powerful magnet, a length of rope, waterproof gloves and a waterway to do some treasure hunting, or ‘magnet fishing’ as it is known.

Examiner reporter Andrew Robinson and four-year-old son Harry joined the Huddersfield-based Team of Yorkshire Metal Detecting Group for a spot of magnet fishing on the Huddersfield Broad Canal.

In just 90 minutes we pulled out piles of junk, a handful of coins, a few keys, several padlocks, a child’s rusty scooter, a mangled bicycle ... and a deadly looking machete.

The machete, found by Marcin Lamch, was handed in to police and the rest was taken to a scrapyard – apart from the pennies which Harry quickly squirrelled away.

The finds were pulled out of the waterway beneath a bridge off Leeds Road.

Team members were a little shocked to find the machete, although in the past they have found bullets during magnet fishing expeditions.

A child's scooter was among items dragged out of the canal during the magnet fishing expedition

Marek Zacharko, a member of the Huddersfield-based metal detecting group, said that objects such as weapons and ammunition were always handed in to the local police station.

He says that there are no law which forbid magnet fishing in the UK.

However, he says that items which are pulled from the water must be disposed of properly and not thrown back in.

“And if we find something that obviously belonged to someone, and is clearly marked, we are obliged to try to contact the legal owner,” he added.

Pile of metal junk pulled out of the canal in Huddersfield by magnet

His own finds while magnet fishing have been modest.

His best find to date was an army field telephone which he believes dates back to the Second World War.

Marek has also found lots of modern coins, old and damaged bicycles and other bits of rubbish.

Finding ‘treasure’ isn’t the real aim, he says.

“It’s a relaxing hobby, a bit like fishing,” he said. “After a working week of stress, it’s relaxing to go magnet fishing. It’s the perfect way to clear your mind. There’s also the excitement of catching something, so I suppose it is like traditional fishing.

“You can’t assume that you are going to get something rare but you might find some coins, which is a nice bonus.”

Unknown metal object pulled from canal by magnet

Marek paid £90 for his own powerful magnet and has pursued the hobby in this country and in his native Poland.

But he does have a word of caution for those who go treasure hunting in his homeland.

“In Poland it is far more dangerous to search in rivers as there are shells and grenades left over from World War Two. It is still risky.”