ADO The Hague gave midfielder Lex Immers the highest possible fine Monday for taking part in a post-match party with fans who appeared to be chanting anti-Semitic slogans.
ADO said in a statement "things happened" at the celebration "which the club's leadership absolutely condemns."
The club did not elaborate, but a video circulating on the Internet appears to show Immers and others standing on a bar while fans chant "We're going hunting Jews!"
The chant was targeting supporters of Ajax, which historically had been identified with Amsterdam's Jewish community. ADO had just beaten Ajax 3-2.
Immers apologized on the club's website Monday, saying he got "carried away in the euphoria of a special victory."
He said he was "not conscious at the time of the insulting tone (of the chant) to an entire group of the population."
ADO spokeswoman Nathalie Nuiten said the club was not releasing the amount Immers was fined, but said he received the maximum penalty which the club could issue.
The Dutch Football Association also said it was investigating the incident _ meaning Immers could yet face disciplinary action.
"In the framework of sporting behavior and respect, this sort of behavior is absolutely unacceptable," said Gijs de Jong, the association's manager of competition.