Adam Levine is introducing a new curse jar policy to The Voice because he has such a "dirty mouth".

The Maroon 5 rocker is one of the judges on the American version of the talent show, alongside Christina Aguilera, Cee Lo Green and Blake Shelton.

Adam is worried he might let slip a profanity when the live shows start next month, so has thought of a way to curb his swearing.

"I have a dirty mouth," he explained to People. "I curse a lot and I want to try to contain that a little bit.

"I'll have a little curse jar next to me. Every time we say a bad word, $100 goes to charity. It will help us, it really will. Because we'll end up giving a lot!"

Adam and Blake have become firm friends since they began work on the programme. Country star Blake is firmly behind Adam's new plan as he thinks he could also benefit from some help when it comes to thinking before he speaks.

"I like that. I'm agreeing to it," Blake laughed. "I will sign up!"

Adam and Blake recently discussed how well they get on. They love teasing each other and enjoy seeing how can get the biggest rise out of the other.

"It's fun. It's just like we're sitting around the bar, making jabs at each other," Blake laughed at the time.