Emma Watson posts picture of Neville Longbottom actor Matthew Lewis playing a soldier in Bluestone 42, leaves Twitter in shock

Matthew Lewis played the awkward student in the Harry Potter movies

Matthew Lewis as a teenager in the Harry Potter movies and now, aged 25 (Getty Images)

He played bumbling, buck-toothed Hogwarts student Neville Longbottom in the Harry Potter movies but now, child star Matthew Lewis has shocked social media...by growing up.

The English actor seems to have suddenly morphed into a 25-year-old, with Twitter users left in disbelief after his friend and former co-star Emma Watson posted a picture of him in BBC3 drama Bluestone 42.

"Always said you were my favourite," Lewis replied, as "Neville Longbottom" immediately began trending.

Bluestone 42, about a group of soldiers serving in a bomb disposal detachment in Afghanistan returns for a third series on Monday at 10pm, and there are no wands or pet toads in sight.

Lewis has appeared in The Syndicate, The Rise and The Sweet Shop since the final Harry Potter film, Harry Potter and the Deathly Hallows: Part 2 reached cinemas in 2011.

His latest photo sees him looking rugged and “very serious” in army uniform, but Lewis insists that fangirl crushes was “never something [he] associated with [himself], ever”.

“I wasn’t attractive when I was growing up and I don’t think I am now,” he told The Mirror in 2012. “It was never, like, ‘Let me takes these ears off then you’ll see’.”