The Australian radio personality, who was allegedly reprimanded by 2DayFM bosses for his numerous days off last year, is now believed to have annoyed advertisers by taking three days off since he returned from his Christmas break last month.
After Sandilands said that he was "unwell", a network insider told The Daily Telegraph: "It hasn't escaped anyone's attention, including advertisers who generally ask for a 'please explain' in these situations. And the worst thing is that Kyle doesn't seem to give a s**t."
After pulling numerous alleged 'sickies' in April last year, Sandilands was forced back to work when his boss "threatened" him with "financial loss". He said at the time: "I'm back at work even though the voice is not better - because an email from the general manager said they'd stop paying me."
Although Sandilands has previously been treated for health concerns including high blood pressure, his co-host Jackie O was believed to be angry that her colleague was spotted socialising with friend Brian McFadden on more than one occasion during his days off in 2011.
In December and January, Sandilands was dropped by various sponsors after launching an on-air tirade about a female journalist who criticised his TV show.
In the rant, he labelled her a "fat slag", a "little troll" and a "piece of s**t" and threatened to "hunt her down".
> Kyle Sandilands under investigation after radio tirade
> Kyle Sandilands bosses at Southern Cross Austereo react to sponsor boycott