Celtic have hit out at "vile" online abuse aimed at Nir Bitton in the wake of last weekend's defeat by Rangers.
The Israel international was the target of abuse including anti-Semitic slurs on social media.
The makeshift centre-back was sent off midway through the second half at Ibrox for denying Light Blues striker Alfredo Morelos a clear goalscoring opportunity.
Neil Lennon's team had been on top before the incident but Bitton's sending off swung the game back in Rangers' favour and Steven Gerrard's Premiership leaders went on to claim a 1-0 win which moved them 19 points clear at the top.
The club said in a statement: "Since its formation in 1888, Celtic has been a club open to all people, with a renowned tradition and ethos of openness and diversity.
"Celtic has forwarded this vile content to the police and considers that everything should be done to identify those responsible and that all appropriate action should be taken. Nir Bitton and his family have our full support.
"We do not believe that it is appropriate to comment further at this stage in connection with this matter.
"Let us be very clear, those responsible for such vile comments do not represent Celtic or Celtic supporters. They are faceless and nameless.
"For certain people to suggest that such comments represent the views of Celtic Football Club is hugely offensive and a disgraceful accusation we take extremely seriously. Nothing could be further from the truth.
"Celtic has always stood firmly against bigotry and racism in all its forms and it is hugely unfair to hold Celtic responsible for the conduct of whoever this may be.
"Social media unfortunately has become a vehicle for some of the worst behaviours, indeed, sadly, our own club, staff and supporters are often the subject of bigotry and racial abuse.
"All content of this kind must be challenged and condemned."