Star slams "unthinkable" Sandilands comment

Australian singer Renée Geyer has condemned "unthinkable" concentration camp comments made by controversial radio host Kyle Sandilands as "offensive and hurtful".

Yesterday, Sandilands sparked outrage by commenting that actress Magda Szubanski - who has lost 25kg and dropped five dress sizes - would lose more weight if she entered a concentration camp.

"I find it absolutely unthinkable that this guy who clearly has no idea of what even occurred in that situation [made those comments]," Geyer said in an interview with Melbourne radio station 3AW.

"I find it very offensive and hurtful… how can he be so blasée and light about something like that?"

An emotional Geyer went on to describe how her mother spent two years in concentration camps at Auschwitz and Mauthausen and witnessed the gassing deaths of her parents.

"My mother was in Auschwitz - her parents were gassed there… she was about 15 years old," the 55-year-old said. "I've seen a picture of her in one of those striped pyjamas - she was like a skeleton."

In July, Kyle and co-host Jackie O were suspended from their top rating radio show following a 14-year-old girl's confession to being raped after being strapped to a lie detector and asked about her sex life live on air.