Magic expert Russ Stevens, credited with teaching her magic tricks, has previously coached magicians on the series.
Britain's Got Talent bosses have denied that Stevens has been a significant presence on set, or had any involvement in helping his granddaughter gain a place on the programme.
In a statement, a Britain's Got Talent spokesperson said: "Russ Stevens is a magic expert, who was used as the freelance magic consultant for two shows only in 2014.
"He has not been contracted since. Issy went through the exact same process as any other act and was auditioned on her performance on the day."
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Russ Stevens is a magic expert, who was used as the freelance magic consultant for two shows only in 2014. He has not been contracted since
Britain's Got Talent spokesperson
Issy appeared on This Morning alongside Eamonn Holmes and Ruth Langsford today where she gushed about her "inspirational" grandad.
The eight-year-old said: "I had a Marvin’s Magic set and I loved Harry Potter, and I watched my grandad do tricks as well."
Child star Issy sat with her mother Jess as she revealed that Ellen DeGeneres had been in touch.
She added: "We’ve been on Skype to them. And, well, if it happens it’s great because I’ve never been to America.
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Issy previously said: "I've been practising on my grandpa. We started with a few tricks, like some card tricks, that were hard then but easy for me now."
Britain's Got Talent refute all fix claims.