The homeless 26-year-old, who has slept rough around Oxford Street for more than six years, vanished after winning through to Boot Camp for his performance of Damien Rice’s Coconut Skins.
Robbie entered the show in a bid to turn his life around, having spent his 20s sleeping rough, unable to hold down a job.
His only point of contact is through a friend, but the X Factor team can no longer reach his this person and haven’t heard from Robbie since last Monday.
Producers – who presumably will be delighted at the extra publicity someone with a genuine sob-story would attract for the show – have deployed a search team to scour the streets, but if he is not found within a fortnight he will lose his place in the competition.
A show insider said: “He doesn’t have a phone and the only point of contact was through a friend. Producers last spoke to him on Monday but they can no longer reach his friend and have no idea where he is. It’s a real worry.
“If he doesn’t get in touch by the end of next week, then he’d have to kiss goodbye to any part in the show, which would be a tragedy.”