Robbie Coltrane is facing his biggest battle as he now uses after his osteoarthritis diagnosis left him in crippling pain.

The 69-year-old star of the Harry Potter franchise, in which he plays friendly giant Rubeus Hagrid, is unable to walk as he waits for knee surgery, that could change his life.

The Cracker actor was launching Hagrid's Magical Creatures Motorbike ride in Universal Orlando, in his first public appearance since using a wheelchair.

Appearing at the press event at the Renaissance Hotel in London, Robbie is "due a new knee," which would give him a chance of “leaping around like an elf.”

(Image: @Blooloop/Twitter) (Image: Mirrorpix)

A source told The Sun that Robbie has been, "in constant pain for years now," and that his knee is, "constantly deteriorating."

The popular actor is hoping to head to the United States for the surgery that will repair his knee but in the meantime Robbie is, "unable to walk without any assistance."

The source also revealed that Robbie was finding the condition "hugely frustrating," and that he is, "hoping to be back on his feet after getting the operation."

Video Loading Video Unavailable Click to play Tap to play The video will start in 8 Cancel Play now

Robbie has opened up previously about how he is coping with osteoarthritis and revealed: "I’m in constant pain all day."

The condition is caused by the breakdown of cartilage and Robbie revealed his knee has, "completely disintegrated."

The last time we saw Robbie on television, in 2016, he appeared with a walking stick in the Channel 4 drama National Treasure.

Do you have a story to sell? Get in touch with us at webcelebs@trinitymirror.com or call us direct 0207 29 33033.