Matthew Lewis felt like he was ''nine years old'' when he saw 'Harry Potter and the Cursed Child'.

The 27-year-old actor - who portrayed Neville Longbottom in the original film series - saw the West End production over the weekend and found the two-part play transported him back to being a fan of author J.K. Rowling's wizarding series.

Sharing a picture of himself and some of the cast from the play, he wrote on Instagram: ''A giant congratulations and an even bigger thank you to these guys and the rest of the cast of #CursedChild. To be in the movies was a dream come true but it became work and I forgot what it was to be a fan a long time ago. However, over the last two nights I was able to enjoy the world of 'Harry Potter' once again.

''To lose myself in a story so rich and so powerful and, more importantly, that I had nothing to do with was truly magical. I felt like I was nine years old again, discovering it all for the first time and it is very, very special.''

Matthew's former co-star, Daniel Radcliffe - who played the titular boy wizard in the movie series - recently admitted he is unsure if he will see 'Harry Potter and the Cursed Child' because he is worried his presence in the audience might distract from what is going on on stage.

He said: ''It would be a weird one. I could be completely wrong in this, but I feel like if I went to see it that night, there's going to be a lot of 'Harry Potter' fans there in the audience obviously and would that then become a thing?

''Would it be more about them watching me watch the show or would it take away from the show. I would never want to do anything that would distract or take away from the show.

''I don't know, I'm not sure.''