Kyle Sandilands blasts Merrick Watts on radio

Kyle Sandilands has been caught having a rant live on air.

The Australian radio and television personality, who presents the 2DayFM breakfast show with Jackie O, used his slot to launch a verbal tirade on boss Adam Lang and rival radio host Merrick Watts.

Sandilands first said of station manager Lang: "What a p*ssant he is... I'll get to him later." The star is believed to be annoyed with Lang for reprimanding him for taking too much time off work but he has now insisted that he has only taken two "sickies" in the past 12 months.

He later referred to Nova DJ Watts as a "fat slob", adding: "They should change their slogan to 'It's over at Nova'. That's how good they're doing."

Earlier this year, Lang was believed to have threatened to dock Sandilands's pay packet. 2DayFM's content director Derek Bargwanna later blamed Sandilands and Jackie O's days off due to "illness" for a slump in audience ratings at the station.

Sandilands was reportedly told in 2008 that he should quit smoking and drinking caffeinated drinks or risk dying young. In March, he was rushed to a Sydney hospital while filming for Australia's Got Talent due to high blood pressure. The following month, he took time off from his radio show because he had "no voice".

He has since reportedly embarked on a fitness regime in a bid to lose weight.