The British heavyweight boxer Dereck Chisora was released from police custody on Sunday, after brawling with his rival David Haye during a post-fight news conference in Munich.
Chisora and Charles were both arrested at Munich airport at 10:30 a.m.
Chisora was initially held on suspicion of assault, causing grievous bodily harm and of making a threat, The Guardian newspaper reports. He and his trainer, Don Charles, were questioned for almost seven hours at Munich police headquarters.
Following his release , police spokesman Gottfried Schlicht told The Associated Press: "He still faces a charge of simple assault but he is allowed to return to England for now."
Chisora and Haye, both from London, came to blows shortly after Chisora's defeat by unanimous decision to Vitali Klitschko in a WBC title fight, the Sydney Morning Herald reports.
BBC Sport says that Haye showed up at the news conference to confront Klitschko, who he believes changed his mind on a potential fight between the pair. But that sparked the brawl, with Chisora and Haye exchanging taunts.
"Either we do it in the ring or outside of the ring. Because I want him. If David don't fight me, Adam, I am telling you the God's honest truth, I am going to physically burn him. If David don't fight me, Adam, I am telling you the God's honest truth, I am going to physically burn him So you tell him I said that," BBC quotes Chisora as saying.
Some reporters fled the scene, until security managed to separate the men.
Chisora's promoter Frank Warren told Sky Sports news that the the brawl "ugly, horrible and disgraceful" and described it as "an embarrassment for British boxing. "I would say they were total idiots."