European football's governing body UEFA could take action after claims that racist chants were made at Thursday night's match between Tottenham and Lazio at White Hart Lane.
Three Spurs players were apparently targeted by some of the Italian club's supporters.
It has also emerged that a Chelsea player has also been racially abused. Chelsea manager Roberto Di Matteo and Arsenal manager Arsene Wenger have said racism in football must stop.
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In a wide-ranging Peston on Sunday interview, he said Parliament security needs reviewing and the PM's counter-terror strategy is flawed.
The terror attack carried out by Khalid Masood at Westminster that left four people dead lasted less than two minutes say police.
Two knives were found at the scene in Islington, North London, and the suspects fled on foot before being arrested.