Barcelona's Cameroon striker Samuel Eto'o said a melee at the end of Tuesday's Champions League match was sparked by a Chelsea steward racially abusing him as he walked towards the players tunnel.

"He called me a monkey," he told reporters after the game. "I understood it. He called me a monkey and I am very angry."

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William Gaillard, UEFA's [Images] Director of Communications said: "If a formal complaint is made of course we will investigate it, but there will have to be some evidence of what happened.

"We will not let it rest if a complaint is made. If one individual has said something we would hope Chelsea will take action, but there must be some neutral witnesses also."

The match, a thunderous, passionate encounter which Chelsea won 4-2 to reach the quarter-finals 5-4 on aggregate, was full of superb football and devoid of any real trouble on the field.

Although the Barca players protested that Chelsea's fourth and deciding goal, scored 14 minutes from time by John Terry, should have been disallowed for a foul by Ricardo Carvalho on keeper Victor Valdes, the match was largely incident-free.

UGLY FRACAS

But there was an ugly fracas at the end. Chelsea's chief scout Andre Villas allegedly insulted the Barcelona bench and spittle was seen flying through the air.

Players and officials were involved in some physical tussles, but the matter was over almost as quickly as it began.

Eto'o added, though: "The mood surrounding the Chelsea bench was ugly, their coach's (Jose Mouirinho's) expression was ugly.

"If Chelsea win the European Cup it would be laughable. They are not a good team, they scored three quick goals because we let them, but the referee was very lenient to them.

"They say he (Pierluigi Collina) is the best referee in the world, I think he is one of the worst."

The tie was surrounded by controversy after an ill-tempered first leg following which Chelsea accused Barcelona coach Frank Rijkaard of attempting to influence match referee Anders Frisk at halftime.

Chelsea are under investigation by UEFA for sending their players late onto the pitch for the second half at the Nou Camp and for failing to attend a post-match press conference in Barcelona.

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