Cologne's Bundesliga match with Mainz on Saturday was postponed after the referee was found to have attempted suicide.
Babak Rafati was found in his hotel room ahead of the game in a state of distress.
Cologne's official website revealed the match was called off because the referee due to officiate was not able to take charge of the contest. The statement added: "A replacement is not available in the short-term."
Bild newspaper quoted Cologne's chairman Claus Horstmann as saying that "he (Rafati) is alive".
At a hastily arranged press conference, Cologne's director of sport Volker Finke explained that the game had been called off "due to an accident".
"It is only considerate and correct that we do not go into details. The rest will be taken care of by the media department of the DFB (German Football Association) and DFL (German Football League)," he said.
"All we can confirm is that the game will not take place due to an accident.
"It was not a decision by Cologne and Mainz and I cannot reveal any further details."