Chelsea have launched an investigation into a number of incidents involving Marseille fans amid claims by the French club's security chief that he was thrown out of Stamford Bridge ahead of their Champions League game.
Head of security, Guy Cazademont, claimed he was "grabbed round the waist'' by Chelsea security officials before being ejected from the stadium.
Cazademont also told the club's official website that Marseille's stewards were not allowed to supervise the club's fans and were ordered to stay seated during the game, while the club's banners were banned in the stadium.
The French champions have promised to refer the matter to UEFA and a spokesman for Chelsea said: "There were a number of incidents at Tuesday evening's game involving the away support, all of which are being fully investigated by Chelsea Football Club.
"We won't be commenting further until those investigations are complete and the results have been shared with UEFA.''
Chelsea won the Champions League Group F clash 2-0 thanks to first-half goals from captain John Terry and from former France international Nicolas Anelka, who scored from the penalty spot.