Tim Minchin's talent has won a big comedy award.

Tim Minchin ... surprising on and off stage, and even on a deserted island. Photo: LRadcliffe@theage.com.au

Fans of long-running UK radio program Desert Island Discs were left spluttering over their marmalade on Sunday after Australian guest Tim Minchin chose a robotic sex doll as his luxury castaway item.

The composer, musician and comedian, who wrote the music and lyrics for hit stage show Matilda The Musical, told the show's host Kirsty Young he would struggle to decide whether to take the doll or his piano.

I assume lots of people say a robotic sex doll? But if it wasn't something to occupy me in that way I'd take my piano. 

Speaking on the Radio 4 show, which invites guests to choose the eight records they would take to a desert island, Minchin said: "I assume lots of people say a robotic sex doll? But if it wasn't something to occupy me in that way I'd take my piano."

Despite that unusual choice, Minchin told Young he was "absolutely conservative of lifestyle".

"I don't think I'm intellectually conservative or socially conservative. I'm quite politically conservative I guess, I'm a pragmatist," Minchin said.

"I don't take drugs, I like jogging, I've been mostly with one girl since I lost my virginity, I like my family, I don't swear in front of kids ... I'm quite boring."

Minchin picked tracks including Waterloo Sunset by The Kinks and I Want You (She's So Heavy) by The Beatles among his choices to play during the radio program.

PA