Heavyweight Dereck Chisora has been released without charge after a brawl with fellow British boxer David Haye. Chisora and his trainer, Don Charles, were taken from the city's airport by police as part of the investigation.
Haye and Chisora clashed at the post-fight press conference after Chisora was beaten on points by defending WBC champion Vitali Klitschko. Police are still searching for Haye, who was not present at the hotel when sought for questioning.
Haye showed up at the news conference to confront Klitschko, who he believes changed his mind on a potential fight between the pair. However, that sparked a verbal exchange with Chisora and the pair squared up to each other before a brawl ensued.
Chisora accused Haye of "glassing him", before saying at least four times that he would shoot the former WBA heavyweight champion.
He added: "If David don't fight me, I am going to physically burn him."
Chisora arrived at the airport to return home, but was stopped by police, who detained him at their Munich headquarters.
A Munich Criminal Police spokesman said: "Police picked up Mr Chisora at the airport at approximately 10.30am [German time] and are bringing him in for the investigation.
"They also picked up Mr Chisora's trainer for questioning. The police went to the hotel to speak to them but we had been informed they had just checked out."
The spokesperson added: "At present we do not know where Mr Haye is.
"We are currently looking for him. He was not at the hotel this morning and we have not seen him at the airport."
Chisora has had part of his fight purse withheld by the World Boxing Council after he slapped Klitschko at the pre-fight weigh-in on Friday.
Chisora appeared to spit water towards Klitschko's brother, Wladimir, moments before Saturday night's bout began.
More controversy followed when Chisora exchanged words with the Klitschko's after the result was announced.
The British Boxing Board of Control has said it will review the incident.