Mad Men star Jon Hamm is convinced Justin Bieber's parents are to blame for the young singer's demise.

The Baby star has been in a downward spiral over the last few months following an arrest on suspicion of drink-driving in Florida and an assault case in his native Canada over allegations the 21 year old was involved in an attack on a limousine driver.

Hamm vented his fury over Bieber's troubles in an interview with America's Men's Health magazine, insisting the star's parents should have done more to help their son.

He says, "Look at Bieber or whoever. You're like, 'What the f**k, man? What are you doing? Why?' There's no one telling those people no, and it's a shame... (He needs) a mom or a dad or a really good friend who can say, 'Hey, s**t head!'... You see people in the world and you're like, 'Do you know how a washing machine works? Do you know how to wash a dish? Life skills are something we're missing... just s**t you needed to learn in life."