Radio shock jock Alan Jones has ended up in hospital suffering from a case of severe back pain.

The 2GB and 4BC brekkie host has been absent from the airwaves since Monday, with Chris Smith – who hosts the lunchtime slot on 2GB – filling in for Jones.

Smith told listeners this morning that doctors are working on determining the exact cause of Jones’ back pain.

“The end result is he’ll be back as soon as he can, but we’re not sure exactly when that will be,” Smith said.

Macquarie Media CEO Adam Lang said in a statement to B&T: “Unfortunately, Alan Jones AO is unwell at the moment and receiving care in a hospital. We hope that Alan is as comfortable as possible and that he has a swift recovery.

“At this stage, we do not know how long that Alan will be unable to broadcast his program. Depending on the required duration of his leave, we will make decisions on who can fill in for him.”

This isn’t the first time Jones has been forced to step away from the mic due to back issues, with the veteran host taking a few months off to recover from surgery in November 2016.