‘Apart from the health issues, he needs to look after his beautiful voice.
‘It’s really not a good look.’
Smoking isn't the only reason the former star has been drawing attention. Jack’s radically changed appearance has been the subject of a lot of comment since he returned to the spotlight, but he insists that he hasn’t had plastic surgery.
‘I’ve never had plastic surgery or any surgery, it’s pretty obvious I have had my lips done with fillers,’ he told the Daily Telegraph.
‘I think with these types of things it’s so common now, especially for people my age, it’s not a big deal. I see it like when you do your makeup or tattoo, it’s all the same.’
As well as hoping for a resurgence in success as a singer, Jack this week announced he’s hoping for another personal breakthrough.
‘Hopefully I’ll find a husband,’ he told New Idea. 'No, I'm happy and single.
‘I'm just grateful for this opportunity and to be let back into people's lounge rooms and share my story.'