Double trouble: uncanny lookalikes that had people fooled

A remarkable thing has just happened. Tom Fletcher, irrepressible lead singer of McFly (and a man who knows a thing or two about the perfect groom's speech at a wedding), created this alternative wedding speech for Prince Harry.

Aside from being hilarious, one of the most jaw-dropping things about it is the extent to which Tom has inhabited the part, recreating his own wedding speech as if he was Prince Harry. And he's surrounded by virtual doppelgängers of the Royal Family, which sent us off digging in the BBC archives for similarly eerie lookalikes and eye-rubbing duplicates.

Needless to say, we've all now got double vision.

This is a firm favourite. As part of his 2015 Student Tour Scott Mills rocked up at Aberystwyth Students' Union with a special guest, ready to man the 1s and 2s, ignite the bass drop and generally get the party started. Could it really be the real David Guetta, superstar DJ and dance producer of legendary status? Well, no. But he really, really looked him, and sometimes that's all you need.

Sarah Mhlanga is constantly being told she looks like Meghan Markle, to such a degree that she can, on occasion, fool the public. A walk through a local nightclub or a London station on the arm of a Prince Harry lookalike may rather lead people to draw that conclusion, but actually it was happening in any case. Speaking to 5 Live’s Anna Foster, Sarah says that certain of Meghan's facial expressions even fool her, leaving her thinking: "Gosh that is me!”

Meet Sam. Sam is one of Seth Rogen's biggest fans, and a man with a slightly worrying wall in his house in Northampton. In 2013, he rang Nick Grimshaw's show to ask Seth a question, and that's exactly what happened. But the thing no one appears to be willing to address in this entire conversation is that Sam is clearly such a colossal fan that he's taken to wearing Seth's face as his own.

Sometimes a lookalike can appear right in front of your face when you least expect it. Greg James was out and about, exploring Bangor in the run-up to Big Weekend 2010, when he went to meet a lady called Claire at Outlook Expeditions. She then introduced him to a very special person in her life, her boyfriend, who is constantly being told he's the spitting image of 'that' Greg James from Radio 1.

But you don't have to be famous to have a doppelganger. Neil Thomas Douglas, an extravagantly bearded photographer from Glasgow, was boarding a flight to Galway when he noticed that the man sitting next to him also had superior facial hair. And a very familiar smile. The weirdest thing is that this gentleman - his spitting image - was sitting in his seat.

Neil told the Guardian: "When I got on the flight, there was a dude already on my seat – when the guy looked up, I thought: 'He looks like me.' We had a big laugh about it – everyone around us had a laugh, we took a selfie and that was it. Later that night, I went to the pub and again, there was my twin. Total weirdness. We had a laugh and a pint."

Not that you have to wait for fate to intervene. Having been introduced to her lookalike Karen via Facebook, Niamh Geaney from Dublin set off to find as many people who share her face as she could, aiming for seven if possible. So far she's found three, and has been cataloguing her experiences on her website Doppelgänger Diaries. She told BBC News: "You do of course question your own identity and your own individuality. You're told all your life about how unique you are as a person... But it's so much more than your face, it's so much more than physical appearance, your identity."

And then there are the people who make a living as celebrity lookalikes, and in the case of Adele tribute acts, soundalikes too. This wonderful clip takes things up a notch by bringing together a group of performers who want to look and sound as much like Adele as possible. Then the real Adele enters proceedings, but she's been made up so that she doesn't look like herself, and is pretending to be another tribute singer called Jenny. But it all falls away when she gets up to perform; that voice is unmistakable.

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