Markus Anfang has resigned as Werder Bremen coach amid a criminal investigation against him for allegedly using a fake coronavirus vaccine certificate which has been seized by authorities.
The German second division club said in a statement that assistant Florian Junge was also stepping down over the probe.
"The reason for the decision is the public prosecutors' investigations into the two coaches and the ensuing unrest surrounding the club," Bremen said.
Anfang said: "Because of the extreme stress caused to the club, the team, my family and myself, I have decided to immediately step down from my role as head coach of Werder Bremen.
"I requested that the club management dissolve my contract, a request they have granted. I wish Werder all the success in the world."
Another assistant, Danijel Zenkovic, was in charge of the team for Saturday's league match at home to Schalke, which ended 1-1.
Bremen's chief executive Klaus Filbry told a news conference at the game: "The decisive factor was that we had another visit from the police at the Weserstadion on Friday evening. There we were given a very clear circumstantial situation."
Bremen managing director Frank Baumann earlier spoke of "a massive allegation" in an interview on the club website and said that things had changed Friday after the club had initially backed Anfang, who had insisted he was vaccinated and used no fake certificate.
"There were fears this could not be cleared up quickly and would drag on. And then it would also impact the sporting area and the image of the club as well," Baumann said.
Prosecutors said they received the vaccination passports from both men, who cooperated with the investigation so that an issued search warrant did not have to be enforced on Friday.
"We will be able to clear up in a timely manner whether the vaccination passport is really false," prosecutor Frank Passade said, adding that Anfang and Junge also handed over other documents.
Bremen's prosecutors' office had confirmed on Friday that it had launched a probe against Anfang after the northern German city's health office filed a criminal complaint.
Anfang did not comment directly on the allegations in Saturday's statement. He had dismissed them in a club statement issued late Thursday.
Australian Associated Press