According to HollywoodLife.com, JB is "devastated" after they apparently ended their romance following a row while on holiday in Mexico, and that he's being trying to patch up their relationship by bombarding Gomez with phone calls.
A source told the website: "Justin's devastated and pathetic right now. He's calling her 100 times a day and she's not picking up.
"[Selena and Justin] flew to Mexico for New Year's Eve, but had a blow-out argument on December 30 and broke up."
They added: "Selena left Mexico that same day and Justin left for Los Angeles on December 31. They haven't seen each other since."
Meanwhile in other Bieber news, TMZ has reported that the Baby singer's team have taken drastic measures after snaps of him apparently smoking a suspicious looking cigarette emerged online over the weekend.
Sources have claimed that Justin's people plan to inform those who that want to party with the star that if they take any pictures of Biebs, the images are automatically his property.
They claim that his team "routinely place a sign in places where Justin parties", with the website adding that the message says "that any and all photos taken at the party do NOT belong to the people who took them - they all belong to JB."
Bieber's fans have also caused controversy on Twitter in wake of the smoking snaps, with the trends #CutForBieber and #CuttingForBieber appearing on the social-networking site alongside images of Beliebers apparently self-harming themselves in a bid to stop JB smoking.