Wicks, 29, is said to have suffered the terrifying ordeal while fishing for food during filming of Celebrity Island with Bear Grylls on an uninhabited Pacific Island.
A source told The Sun Online: “Pete and the rest of the Islanders were checking their fishing nets when he was attacked by the shark. It just came out of nowhere and bit his hand.
“It was terrifying. There was blood everywhere and everyone was panicking and trying to run out of the water.”
Wicks, who dates fellow TOWIE star Shelby Tribble, flashed his bandaged hand in an Instagram story after being reunited with his dogs on returning home from his five week stint on the gruelling Channel 4 show.
Standard Online has contacted a representative for Wicks for comment.
Wicks lost three stone while filming and said he struggled to gain the weight on returning to the UK.
Speaking about his time on the show he said: “You think you're going to be able to come back and scoff as much as you want, but you physically can't.
“I’ve been really struggling ever since. It's the hardest thing I've ever done, without a doubt.”
It comes a year after former TOWIE star Lucy Mecklenburgh shocked fans with her dramatic two stone weight loss.
Mecklenburgh, who met her boyfriend Ryan Thomas on the show, posted a before and after shot on Instagram alongside the caption: “My poor little body!!!! Soooooo emotional watching the last ep of #celebrityisland .. I can't believe we did it.. I can't believe I did it what an experience!
“I will never doubt myself ever again!! Met some incredible people that will be friends for life. So proud of us all!!”