Nick Carter has warned his brother Aaron that he will be sued if he tells lies about him.

The pair have a notoriously fractured relationship and, according to The Blast, Nick recently hit back at Aaron with a legal letter after the younger sibling spoke out about their personal drama.

The website reports that Nick told Aaron he will "have serious legal issues" if he lies about him in public.

After Aaron received the legal letter, he reportedly ditched plans for a new reality TV show.

Nick, 37, is reportedly concerned for his 29-year-old brother, who checked into rehab this week, and wants to repair their relationship.

However, before he entered rehab, Aaron revealed that he no longer has any contact with his family and explained that his "stressors haven't subsided" with them.

He said: "I would like to tell all of you that I will be disappearing for a while to work on myself ... My stressors haven't subsided with family and this year has been crazy and I need some time off from all of it. Going to get strong. And deal with my stress conditions and get better.

"Only I can change my life. No one can do it for me. Talk to y'all in 2018.

"And FYI. MY FAMILY has nothing to do with this. I've actually had to cut them all off unfortunately and it's gonna stay that way.

"We can talk about this when I'm done taking care of myself. that goes to everyone especially the medias. I'm gonna have a lot to say. Thanks

"I am strong, that's why I made this decision. No one could've forced me. None of you even know my reasons for this. It's called stress.

"My big come back is getting strong again physically did y'all not see on the doctors about my stress conditions yet they throw it in my face

"See y'all on tour next year. You won't be hearing from me until then. Thx. I do LoVe you all. So much (sic)."