Neymar says he "crossed the line" as he apologised to his Santos team-mate Robinho Jr for slapping the teenager during a training session.

The Brazilian club opened an investigation after the 18-year-old forward reportedly accused Neymar of delivering "a violent slap to the face" on Sunday after he had dribbled past the 34-year-old.

They have now cleared the air and said on Tuesday the incident at the Rei Pele Training Centre was "all sorted".

"If you want an apology in front of the media, here it is," added Neymar, who is Brazil's all-time leading goalscorer with 79 goals.

The former Barcelona and Paris St-Germain forward celebrated scoring for Santos during Tuesday's 1-1 draw with Recoleta in the Copa Sudamericana by hugging substitute Robinho Jr, who is the son of his former Brazil team-mate, and ex-Manchester City and Real Madrid attacker, Robinho.

"I did overreact, yes, in the way I reacted. It could have been different but I ended up losing my head," added Neymar.

"Everyone makes mistakes. It was my mistake, his mistake, I made a slightly bigger mistake.

"He's a boy I like very much, for whom I have a special affection. It happens in football - you argue with your friend, your brother.

"That's football, it's part of the game."

Robinho Jr said Neymar "realised straight away that he'd gone too far" and apologised "several times" for the altercation.

"It was a situation that upset me because [Neymar] has been my idol since I was a child," he added.

"People around us say a lot of things that aren't true and it's sad to see it blow up to this level.

"But I'm fine, I like him a lot. We've already talked and it's all sorted."