A former child star, Matthew Lewis will do well to escape comparisons with his 12-year-old Harry Potter alter ego.

But the heartthrob - who this month takes the role of a triathlete in Me Before You - is barely recognisable in a new seriously sexy shoot for Attitude magazine.

The 25-year-old is sure to win the hearts of female and male admirers alike with his most recent shirtless snaps, that see him strip down to a pair of (very) smalls.

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Transformation: Screen hunk Matthew Lewis shows off his newly-ripped physique for Attitude magazine as he prepares to play a triathlete in rom-com Me Before You

Matthew - baring a striking resemblance to that transformative Calvin Harris Emporio Armani shoot - sports just a pair of briefs while reclining on a bar stool in the new men's magazine shots.

The actor formerly known as Neville Longbottom exposes his newly-ripped chest with a wholesome knitted cardigan left open around his shoulders to soften his rock hard physique.

Meanwhile, the cover shot for June's 'swimwear and underwear special' is equally enticing and the actor is seen stripping off his vest to reveal an impressive six pack.

The child actor's transformation came to light as far back as 2012 when he took to the West End stage, but now Lewis is getting set to play an uber-fit personal trainer - and his commitment to the physicality of the role was very apparent when he chatted all things fitness with Attitude.

Stripping off: The former child star shows off his six pack on the cover of June's swimwear and underwear special

Collectables: Matthew is just one of the covers for this month's issue of the magazine for men

Matthew spent 10 years wearing a fat suit and prosthetics to play JK Rowling’s nerdy Gryffindor student but now says he's off carbs, alcohol and even shaved his leg hair for the romantic comedy role.

Matthew says of his character Patrick: 'I spoke to the director and I said it’d be nice to get into the mindset of someone like Patrick, because he’s not drinking alcohol, he’s just eating salads all the time.

'I was very interested to know where you go to in your mind to have that level of commitment. So I sort of gave up alcohol – I say sort of, I have given up alcohol.'

Though it's not been an easy ride for the hunky heartthrob - who is taking on the film role alongside The Hunger Games star Sam Claflin and Game Of Thrones' Emilia Clarke.

'It’s tough,' he added. 'I do the pub quiz every week, and I'm sitting there every Wednesday with a Diet Coke... I’m off sugar and I can’t really eat carbs.

'I really wanted to see if I could stick to such a strict regime, and to really understand what it’s like to have a goal like that and really 110% go for it.

Transformed: Matthew (pictured in May 2015) cut a very different appearance to his former red carpet days like Harry Potter And The Goblet Of Fire premiere in November 2005, aged 15

Flashback: Matthew played Neville Longbottom (pictured second left), starred alongside Emma Watson (front) as Hermione Granger and Devon Murray (left, as Seamus Finnigan), as well as James and Oliver Phelps (far left and right) as the Weasley twins

Similar story: Calvin Harris (left, pictured for Emporio Armani underwear in 2014) shocked fans when he showed off a very similar physical transformation from his nerdy breakthrough in 2007 (pictured right)

'I mean I’ve always been a bit of a sports enthusiast anyway, I love the gym and all that stuff, but I can’t wait for a pint of lager, I tell you that! The pizza and beer will definitely be making a comeback over the summer.'

Matthew has obviously had to put in plenty of effort to achieve the body of fitness-obsessed Patrick and recently admitted on Twitter that he has a love-hat relationship with his own personal trainer.

'My personal trainer once again proving that it’s possible to absolutely hate your favourite person in the world. At least for 4 sets of 15.'

In the film, an adaptation of the best-selling novel by JoJo Moyes, Matthew plays Patrick the boyfriend of Emilia's character Louisa Clark.

Behind the scenes: Matthew shared a shirtless picture for his Instagram to prove that the Attitude shoot was a pretty chilly one when he stripped off

Love hate relationship: Matthew admitted that he had a love-hate relationship with his personal trainer

Louisa is a small-town girl who strikes up a bond with a recently-paralysed man Will Traynor (played by Sam Claflin) and discovers that she might not be so in love with Patrick any more.

While, Mr Lewis has enjoyed small acting parts since leaving the eight-part Potter franchise, he will always be best remembered for Neville.

And like lead actors Emma Watson (Hermione Granger), Rupert Grint (Ron Weasley) and Daniel Radcliffe (Harry Potter), he had to endure red carpet appearances with braces and all of the added awkwardness of being a teenager in the spotlight.

In time for the final film Harry Potter and the Deathly Hallows: Part II, which was released in 2011, the actor said people were starting to realise he didn't look so similar to Neville Longbottom.

His new leading lady: Matthew has been filming with Game Of Thrones actress Emilia Clarke in Wales for Me Before You

Rom-com heartthrobs: Matthew has been male bonding with his co-star Sam Claflin (right)

Matthew made quite an impact at the world premiere and reflecting on the spectacle said: 'I was excited I guess to go on the red carpet on the release of the last film and be me, and not to have to have the fat suit under my t-shirt. It was quite an exciting buzz.

'I was 21, I was like "yeah, this’ll be cool!" It was never meant to be a "hey everyone, look at me!" but it was nice to be able to go and be myself.

'And then obviously a lot of attention focused on it, which I didn’t expect at all. I’ve never considered myself to be good-looking at all. Just average.'

Read the full interview with Matthew Lewis in the June 2015 issue of Attitude magazine, on newsstands now.

Commitment to the cause: Matthew (right) stars alongside Emilia Clarke as Louisa Clark in the new novel adaptation