Tottenham manager Mauricio Pochettino was angered by the "unacceptable" anti-Semitic banner displayed by Partizan Belgrade fans in their Europa League opener.
Spurs' 0-0 draw was overshadowed by an anti-Semitic banner in the home end, inspired by the "Only Fools and Horses" logo.
The name was changed to "Only Jews and Pussies" and was displayed at Partizan Stadium throughout the match.
Uefa is investigating the issue pointed out to them by Tottenham officials, with a delegate from the governing body taking photographic evidence after the match.
"I didn't see it," Spurs boss Pochettino said. "The club is aware but I did not see [it myself]. But if this is true, then it is an unacceptable thing. It is very disrespectful. This is a shame, very disrespectful and unacceptable."
It is not the first time Partizan have found themselves in hot water, having been thrown out of the UEFA Cup and fined in 2007 for rioting during a first qualifying round first-leg clash at Zrinjski Mostar.
Thursday's incident also came just two years on from the disgusting racial abuse suffered by England Under-21s in a European Championship play-off in Serbia.
Spurs left-back Danny Rose was caught up in the problems that night and was among those rested for the clash with Partizan.