Giovanni Pernice, 29, was reportedly attacked by the thieves during an evening in Epping, Essex, last month.
During the robbery, Giovanni was sprayed in the eyes by a noxious substance, believed to be pepper spray, according to The Sun.
But at first, the Strictly Come Dancing professional reportedly thought it was acid as the substance burned his eyes.
The attackers got away with the Italian dancer’s watch and rucksack, it’s been claimed.
The publication reported Giovanni was approached by men in a black car as he was about to get into an Uber.
The Strictly Come Dancing favourite, who will be in the launch show tomorrow, was treated by paramedics at the scene.
A source told The Sun: “His first thought was that it was an acid attack — because of the burning in his eyes.
“He has been left absolutely terrified by the attack. It has hugely knocked his confidence.”
The source told the publication, Giovanni’s girlfriend, Ashley Roberts, who he met on Strictly Come Dancinglast year, was “shaken” by the news.
Express.co.uk has contacted Giovanni’s representative for comment .
Ashley declared her love for her beau on Instagram earlier in the week, as she marked his 29th birthday.
The singer, who was partnered with Pasha Kovalev on the BBC competition last year, shared a series of images of her beau.
She gushed in the caption: “Happy Birthday my spicy Italian stallion.
“Never woulda guessed after getting ask to do a sparkly dancing show that I would meet my best friend. Celebrating you today and always. TANTO”
Giovanni replied on her post: “I love you baby!! per sempre [forever].”
Meanwhile, Giovanni appears to be moving on from the awful attack and has been sharing his excitement about this year’s series.
Teasing who his partner could be on the show this time round, Giovanni uploaded photos of his previous celebrity pairings.
“Not long to go,” he said. “Who will my 5th celebrity partner be? What do you think? Leave a comment below of who your guess is.”
Strictly Come Dancing airs Saturday on BBC One at 7.10pm.
