German prosecutors told BBC Sport on Monday that both fighters are suspected of committing offences that could carry prison terms.
Haye is suspected of grievous bodily harm - a crime which, if proven, carries a prison sentence of six months to 10 years.
Chisora, who admitted his behaviour was "inexcusable", is under suspicion of malicious injury, which carries a jail sentence of up to five years, and making a "threat". The latter is a lesser offence punishable by a fine or imprisonment of up to one year.
from Zimbabwean-born Chisora revealed he was sorry for his "part in the regrettable scenes both before and after what was to be the biggest night of my career".
He added: "While my behaviour was inexcusable, there were many things that went on behind the scenes that ultimately caused my frustrations to boil over, however this is of course no excuse."
Haye, who has retired from boxing but was at the fight working as a television pundit, added in
"I realise I am no angel - and don't mind a bit of professional trash-talk to help raise boxing's profile - but, during my 21 years in the sport, I have never been involved in, or even witnessed, such a serious fracas."
Haye, who has now returned home, left the country on a plane before he could be questioned but German police still want to speak to him.
Chisora and his trainer Don Charles were arrested at Munich airport before being released without charge on Sunday evening.
On top of a police investigation, the British Boxing Board of Control (BBBofC) general secretary, Robert Smith, says Haye and Chisora could face life bans from the sport.
Dereck Chisora in bloody brawl with David Haye
"It's a possibility," Smith told BBC Radio 5 live. "The board have many powers. They can fine, they can suspend and they can withdraw a licence."
The BBBofC have confirmed that Chisora has been called to appear before hearing on 14 March in relation to his conduct before and after the fight with Klitschko.
The president of the Federation of German Professional Boxers, Dr Thomas Put, told BBC Sport Chisora should get a lifetime ban from the sport, admitting "he should never fight anywhere".
But Haye's trainer Adam Booth, who claimed Haye was acting in self defence, told BBC Radio 5 live: "If Dereck has apologised, then he deserves respect for that and I hope he goes on and has a successful boxing career."
Although Haye has retired from the sport, the board could choose to effectively ban him by denying him a licence if he seeks to fight again. However, Booth told 5 live on Monday he would only come out of retirement to fight one of the Kiltschkos.
The scenes unfolded after Haye showed up at the news conference to confront Vitali Klitschko, who he believes changed his mind on a potential fight between the pair.
But that sparked a verbal exchange with Haye and Chisora squaring up to each other before a brawl ensued.
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