The 'Sex On Fire' hitmakers called off their entire US tour following a concert in Dallas, Texas on Saturday (30.07.11) where Caleb walked off stage blaming the heat and while his brother Jared has hinted at more serious problems on his twitter page, it is believed those close to the singer are worried his drinking may have gotten out of control.
A source told USmagazine.com: "They are trying to get Caleb to go to rehab. It is mostly for alcohol."
A second source added: "It's true. Caleb's drinking is out of control and they are trying to get him into rehab. It's a dark demon he has been fighting for awhile."
After Saturday's debacle and the announcement that the band would not play the remainder of their US concert dates, bassist Jared wrote on twitter: "There are internal sicknesses & problems that have needed to be addressed. I know you guys aren't stupid. I can't lie. There are problems in our band bigger than not drinking enough Gatorade.
"Utterly depressed. It's completely out of my hands. Family has to come 1st. (sic)"
However, a representative for the band denied the claims, saying Caleb has been advised to rest his vocal chords by a doctor.
The representative said: "Caleb is under doctor's orders for vocal rest. They feel terrible about [calling off the tour]. They look forward to getting back on the road at the end of September."