A romantic boyfriend sprung a surprise proposal on his stunned girlfriend - by letting her ‘discover’ an engagement ring during a metal detecting outing.

Jamille Swainson, 31, from Wendover, hid the sapphire and diamond studded ring in the ground before taking Harriet Haseler, 30, on an ‘activities day’ which included a session using metal detectors.

Excited Harriet detected an 18th Century penny, a musket ball, a silver sixpence and a silver Victorian locket - before coming across a metal box shaped like a military drum.

When she opened it there was a hessian sack inside where the ring was being hidden.

Jamille said: “I asked her to have a look inside the hessian sack and then went down on one knee. She was speechless.”

Harriet agreed to marry Jamille whom she had dated for two years after the couple met on dating site Tinder.

Harriet said: “We had been finding things all morning, so I thought it could be some kind of penny.

“I then found an old tin which opened and inside I found an old bag with this gorgeous shiny new ring inside.

“I was speechless and couldn’t stop smiling, I was beaming.

“It was the most amazing feeling and I couldn’t believe how sweet the proposal was.”

Jamille hit on the unusual proposal idea after telling Jamille of her fond memories of going metal detecting with her grandmother on a farm in Buckinghamshire.

Jamille said: “Harriet had mentioned a few times that she wanted to go metal detecting as a family so I thought it would be a great way to propose.

“A big proposal didn’t interest me at first but my relationship with Harriet continued to surprise me and she changed my mind without even knowing it.”

“I started planning it in August and got in touch with Chris Langston who runs the metal detecting company.”

After asking permission from Harriet’s father and seeking advice from Harriet’s twin sister, Scarlett, Jamille set to work on finding the perfect ring.

He said: “She never wears jewellery so I had nothing to base it on but Scarlett told me that Harriet liked sapphires.

“I had the ring made at Alan Bick in Hatton Gardens and I had the pleasure of hand picking the individual stones, band and setting of the ring.”

After careful planning, Jamille settled on a ring with a 1.5 carat sapphire surrounded by a cluster of diamonds on a yellow gold band also covered in diamonds.

According to Alan Bick, these types of rings can cost upwards of £2,000.

Jamille organised the proposal to fall on the weekend of Harriet’s 30th birthday.

He said: “I planned a surprise weekend away for her birthday, she didn’t even know where we were going until the week before.

“I told her that I had some activities planned for the weekend but she didn’t work out that we were going metal detecting until she saw the detectors in the back of the van.”

Jamille, a builder, had given the engagement ring to Chris the night before so that it could be hidden.

The couple then went with Chris to a nearby paddock in Whittington, Shropshire, where they were joined by a horse called Crunchy as they spent two hours metal detecting.

Jamille is now planning to get the silver locket that Harriet found fixed so that she will be able to wear it as a reminder of the happy day.

Both Harriet and Jamille have children from previous relationships.

Ever since Harriet’s six-year-old daughter, Lyla, found out the news she has been insisting that she and Jamille perform a Strictly Come Dancing style dance at the wedding.

Jamille said: “It’s really nice that this has all happened and Harriet will never forget our special day. I kind of feel like I nailed it.”

The couple have already started planning for the big day., deciding that they don’t want a formal wedding because they both have such a passion for the outdoors.

Harriet has already started looking into booking the same venue where Jamille’s father was married a couple of years ago - a barn and cottages in Devon.

Jamille said: “We want it to be very relaxed so we’ll be keeping it quite small and the guest list will definitely be under 80 people.”