Chelsea FC have pledged to find and ban supporters filmed singing antisemitic songs about rivals Tottenham at a match last month.
Clips of fans chanting in a concourse at Stoke City’s Britannia Stadium were posted on YouTube, leading Spurs to complain to the west London club.
They can be heard singing "Spurs are on their way to Auschwitz" while beer bottles are thrown around.
Chelsea, owned by Roman Abramovich, said they had passed the clips to police who are now investigating.
In a statement, the club said: “Chelsea utterly condemns all forms of discrimination, including antisemitic chanting, as we are sure do the vast majority of our fans.
“If we are provided with evidence that season ticket-holders or members have engaged in such activity we will take the strongest possible action, including supporting criminal prosecution.”
It is thought the Football Association could ask Stoke to hand over CCTV footage from inside the stadium. A number of fans’ faces are visible in the clips.
Chelsea have previously banned supporters from singing antisemitic songs at its Stamford Bridge ground.