Prime Minister John Key says his son, Max, is "vehemently opposed" to smoking, despite modelling shots that show him with an unlit cigarette.
Max is being criticised for promoting smoking after posting a professional photo to his Instagram account.
It shows him wearing Calvin Klein underwear, with an American flag headband and holding the unlit cigarette between his fingers.
Photos from the shoot appear in the latest edition of Remix Magazine and include an interview with the newly turned 21-year-old.
His dad came to his son's defence today, approving of the photos and saying Max didn't approve of smoking.
"I think it's pretty cool. He's a young guy; he's a man now. He's capable of doing his own things and it's quite cool. The photos look good.
"In the end, people when they're doing modelling shoots are often asked to do things they don't do themselves.
"He's actually vehemently opposed to smoking. To the best of my knowledge, he's never smoked," he said.
Mr Key said Max has talked to him about being against smoking.
When asked whether he was as "toned" as Max at his age, Mr Key replied: "I don't think so. I wish I was" before smiling and walking away from media.