Captured South African journalist Shiraaz Mohamed is alive in Syria and could be home within a month.
Chisora, beaten by Ukrainian Vitali Klitschko in a unanimous points decision in their heavyweight title bout in Munich, has already been questioned and released by police over the incident at the post-fight news conference.
"Of course we still want to talk to Mr Haye and question him to find out about his involvement," said Munich police spokesman Wolfgang Wenger. "There are investigations centred on him and the prosecutor will decide how to get hold of him, whether this will happen in England or here."
The British Boxing Board of Control (BBBC) has ordered Chisora to appear at a hearing on March 14 to explain his part in the scenes during the post-fight press conference and before the fight when he slapped Klitschko at the weigh-in.
Chisora apologised for his behaviour on Monday: "I have let down my family, my team and worst of all the sport I love."
Haye had been attending a news conference as a TV pundit. He exchanged comments with Klitschko's manager and Chisora and the situation degenerated when Chisora confronted his fellow Briton and the pair traded blows. The BBBC said both Chisora and Haye, who retired in October, could face life bans.7