Authenticating Collectors item?

[Paul7508]

Hello, I'm writing to who ever is able to contact Harry Kewell, as I'm in the search of having a signed shirt of Harry Kewell authenticated as I won a competition which the price was a 1.1m x 1.2m framed shirt personally autographed apparently by Harry Kewel,l Liverpool team shirt along with photos and stat plaque. (Please see attached photo). Unfortunately there was no certificate of authenticity provided and the only way I am able to supply such a document is from the person who signed it.... Which I am hoping is that of Harry Kewell. If it's not too much trouble could someone please help me in possibly finding out some information regarding to getting such a document from the man himself. I could not attach file but I am able to attach to an email if someone requires. Please email me at doogsie70@hotmail.com. Thankyou