Norwich - Police and Norwich City are investigating an alleged racist message posted about the club's manager Chris Hughton on an unofficial Facebook page.
"Following last weekend's victory for the Canaries away to Stoke, unacceptable terminology was used on the Facebook page '**OFFICIAL**!!! Ipswich - Norwich fans banter/insult/joke page'," the English Premier League club said on their website on Thursday.
"It should be stressed the site is in no way officially affiliated to either club."
East Anglian sides Ipswich and Norwich are fierce rivals.
Norwich said the matter had been raised by Kick It Out, football's equality and inclusion campaign, who had reported it to police as a hate crime.
"We are in dialogue with Kick It Out and Ipswich Town and will co-operate fully with the police investigation into the incident," Norwich said.
"We have a zero tolerance policy on racism and all other forms of discrimination and any supporter found guilty of racist abuse faces a lifetime ban from Carrow Road in addition to any punishment handed out by the courts."