The Big Brother winner was out celebrating her 29th birthday in Bristol with friends and family last night when the attack took place.
It is understood Harry, who is deaf, was approached by at least two men who asked him for directions.
When he started to sign a reply rather than speaking aloud, the callous thugs turned on him and beat him up.
A distraught Josie later tweeted a picture of Harry covered in blood.
Lost all faith in man kind tonight. I went to the toilet and my brother got beaten up for being deaf!!! What a disgusting world we live in!
— Josie Gibson (@Josiestweet) January 26, 2014
"I'm going to hunt the bullies who did this!The nicest guy ever was
beaten up because they thought he was deaf & dumb," she wrote.Josie won Big Brother in 2010 and has gone on to be a TV presenter.