Chelsea's 2-1 defeat by Barcelona in the Champions League ended in controversy with managers Jose Mourinho and Frank Rijkaard involved in a row about an alleged halftime "incident".

Mourinho refused to make any public comments after Wednesday's game and stopped his players doing interviews. His spokesman Simon Greenberg told reporters Chelsea would make a report to UEFA [Images] about "an incident at halftime".

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Barcelona sources said the two managers' assistants were involved in an argument in the tunnel at halftime after Rijkaard spoke to Swedish referee Anders Frisk.

Rijkaard told a news conference he was curious to know what would be in Chelsea's report to UEFA and felt the row had been blown out of proportion by the London [Images] club.

"I don't understand this behaviour and I don't think it's correct," Rijkaard said.

"I just said hello to him [the referee] and said something about the game but in a friendly way so the reaction of some of the Chelsea side was a bit exaggerated.

"We didn't start anything and I just talked to him but not in an aggressive way," the former Netherlands international added.

ARGUMENT

The Barcelona bench went into the tunnel complaining about Chelsea's first-half goal, which they believed was offside, Barcelona sources said.

Chelsea officials objected to Rijkaard approaching the referee and an argument broke out between backroom staff on both sides, they said.

Chelsea's goal arrived against the run of play from a pass upfield by Frank Lampard [Images] to Damien Duff. Duff's cross was inadvertently booted into his own goal by Juliano Belletti.

Rijkaard attempted to play down the row.

"I am curious as to what will be the declaration of Chelsea, Nothing happened," Rijkaard said.

"Every trainer can talk as much as they want. I don't complain about that. I think it's a surprise that after the game they invented a story that didn't happen."

Mourinho has a history of complaining about rival managers' behaviour with referees.

Last month he was critical of Manchester United [Images] manager Alex Ferguson's halftime discussion with the referee during their 0-0 League Cup draw at Stamford Bridge.

"There was a lot of talking before the game and now there is a lot after. I don't think it's good behaviour," Rijkaard said. He denied rumours the referee had entered Barcelona's dressing room after the match.

Chelsea were due to return to London late on Wednesday to begin preparations for their League Cup final against Liverpool on Sunday.

The return leg against Barcelona is scheduled for March 8 at Stamford Bridge.

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