Bryan Singer found it "traumatising" to let go of the 'X-Men' franchise after giving up the director's chair to Brett Ratner for 2006's 'X-Men: The Last Stand'.

Bryan Singer found it "traumatising" to let go of the 'X-Men' franchise.

The 'Jack the Giant Slayer' director - who helmed the first two installments in the superhero franchise, before giving up the reins to Brett Ratner and Matthew Vaughn on two subsequent films - has admitted it was difficult to see someone else direct the series he helped bring to life on the big screen.

In an interview with the Metro newspaper, he said: "I've never told anybody this, but I found the whole letting go of the characters for 'X-Men 3' ['The Last Stand'] so traumatising that a friend, who shall remain nameless, had to take me to a secret location and show me the reels so far, just so I could make my peace with it."

The filmmaker is set to return to the mutant hero series for next year's 'X-Men: Days of Future Past', which will unite cast members from the original 'X-Men' trilogy - including Hugh Jackman, Sir Patrick Stewart and Sir Ian McKellen - and 2011 prequel 'X-Men: First Class', which featured James McAvoy, Michael Fassbender and Jennifer Lawrence.

Singer's latest film 'Jack the Giant Slayer', which is a new take on the classic 'Jack and the Beanstalk' fairy tale, is considerably light-hearted compared to the superhero movies he's famed for.

He explained: "The main difference between them is that unlike superhero movies, fairy tales don't run on testosterone. With 'Jack', I looked more to films like 'The Princess Bride', 'Pirates of the Caribbean' and 'Jurassic Park' for the tone."