For the second time in six months, 3AW Drive host Derryn Hinch is battling a mystery illness.

Hinch was reportedly checked into Cabrini hospital in the Melbourne suburb of Malvern last week with some kind of blood poisoning, possibly septicaemia.

The presenter has no idea when he will return to the airwaves, telling News Limited newspapers yesterday “I can’t tell you because they (doctors) haven’t told me.”