The 27-year-old diva shot to fame last year after winning reality TV show, The Voice, in Italy. The video of the audition was the fourth most watched video worldwide on YouTube in 2014.
But fame is not without its drawbacks. The Belgian superfan had allegedly been causing the nun problems for a while, with Sister Cristina reporting him to the police after he bombarded her with private messages and wall posts on Facebook.
But some sisters close to the nun last week identified the fanatic and reported him after he allegedly chased Sister Cristina in a bid to get a selfie with her.
The man was arrested for stalking and has been taken to a centre for deportation and immigration in Bari, where he'll await deportation to Belgium.
Months after winning the talent contest, Sister Cristina released her first album, sparking controversy among Church traditionalists with a cover version of Madonna's racy 1984 hit, Like a Virgin.
Read more: Italian nun releases Madonna-inspired album