Aaron Carter has alleged Michael Jackson did "one thing that was a little bit inappropriate".
The 'I Want Candy' hitmaker recently vowed to tell his story about the late King of Pop - who passed away in 2009 - after he was accused by Wade Robson and James Safechuck in the HBO documentary 'Leaving Neverland' of sexual abuse after he befriended them both as children.
And in a clip for an upcoming episode of 'Marriage Boot Camp: Reality Stars Family Edition', the 31-year-old singer can be heard initially defending the 'Thriller' hitmaker by claiming he was "a really good guy", before alleging there was one time where he acted inappropriately.
He says in interview footage from the WE series which was obtained by People magazine: "Michael was a really good guy, as far as I know, a really good guy. He never did anything that was inappropriate. Except for one time. There was one thing that he did that was a little bit inappropriate."
Aaron doesn't elaborate further on his allegations, and hasn't stated whether his claims relate to an act he witnessed, or if the alleged "inappropriate" behaviour was directed toward him.
Last month, the singer - who previously slammed Wade and James as "liars" - has said he plans to speak about his own experiences with Michael "in the future".
He said: "To be honest, after seeing everyone's stories unfold, I was a little aggressive. I mean everyone has their own stories, and everyone has their own situations, so you know, I can't really take away from that. I don't know, so I can't say 'Oh I was there, I was a fly on the wall.' Because I don't.
"In regards to that situation, I actually have my own experience that happened with Michael, so I'm going to be talking about that in the future."
And Aaron wouldn't reveal whether his experience involves alleged abuse, but did say he will "tell [his] truth".
When asked if he was abused by Michael, Aaron said: "You're just going to have to find out when I talk about. You're just going to have to find out."