A young boy’s dreams have come true after a mystery donor pays for £10,000 bionic ‘Iron Man’s arm.

The nine-year-old boy had always dreamed of being able to cast his fishing rod with his dad and luckily his dreams are coming true after he was fitted with a £10,000 bionic ‘Iron Man’ arm – which was paid for by a mystery donor.

Billy Gregson was born with his right arm shorter than his left, with limited movement, due to an upper limb congenital deficiency.

The nine-year-old had hoped that his arm would grow back so he could “be like his friends” and go fishing with dad Mark, 54, without needing his help.

Billy’s mother; Donna, began researching potential solutions and came across a leading prosthetics firm OpenBionics who could make a high-tech arm for him.

Due to the cost, the 49-year-old was forced to fundraise but was blown away when an anonymous donor later gifted them £10,000.

After the device was fitted recently, Donna said Billy was “over the moon” and his confidence had “boomed”.

“He wears it for school every day. His face when he received it was a picture. He was over the moon. He said it’s like Christmas. It was all he asked for.”

Billy, who lives with his family in Leeds, Yorkshire, has a congenital limb defect, which is when an arm or leg doesn’t form normally as a baby grows in the uterus. The exact cause is unknown, and in Billy’s case, doctors didn’t recognize any issues with his arms until he was born.

Donna said she first came across the “hero arm”, made by Bristol-based company OpenBionics when she began researching their ambassador Tilly Lockey.

The 16-year old double-amputee has used her two “hero arms” since she was eight, and won the sixth series of the CBBC show Got What It Takes?

Billy’s new bionic arm uses sensors within the casing to allow him to respond to movements and is designed to act like a real arm.

Since his fitting, Donna said Billy is now learning how to use the arm to achieve his goals, which include fishing, one of his favourite hobbies.

Samantha Payne, MBE, COO at Open Bionics, said the company was “so happy to hear Billy is set to continue his Hero Arm journey”.

She added: “We’re grateful to the donor and we’re hopeful that NHS England will make the decision soon to give access to multi-grip bionic arms to arm amputees. “They deserve access to this technology as it has a huge impact on their daily living and mental health.”