Uefa has begun disciplinary proceedings against Chelsea, their manager Jose Mourinho and two other club officials.
Uefa looked into Chelsea's claim that Barcelona coach Frank Rijkaard entered the referee's room at half-time in February's game between the clubs.
Chelsea, Mourinho, assistant manager Steve Clarke and security official Les Miles have all been charged with bringing the game into disrepute.
Their claim was "wrong and unfounded" according to Uefa.
Uefa spokesman William Gaillard told BBC Five Live that thowing Chelsea out of the Champions League was a possibility.
"The punishment goes from a simple warning to disqualification of the team. It's for the disciplinary body to decide," he said.
Chelsea are reviewing their position before responding.
The charges come after a bitter row between the Premiership leaders and Uefa, which followed that Champions League last-16, first-leg match.
Chelsea lost the first leg 2-1 but went through to the quarter-finals - where they will play Bayern Munich - after triumphing 4-2 in the second leg at Stamford Bridge.
SANCTIONS OPEN TO UEFA
Blues boss Mourinho failed to appear at his mandatory media conference after the first leg, with Chelsea issuing a statement declaring that there had been "an incident" at half-time they were unhappy with.
It later emerged that the Blues had complained to Uefa that Barca coach Rikjaard entered Frisk's room, which was immediately denied by Rijkaard and the official.
"When I saw Rijkaard entering the referee's dressing room I couldn't believe it," Mourinho was quoted as saying on 27 February.
"When Didier Drogba was sent off I didn't get surprised."
However, Gaillard said Chelsea's claims were false.
"It is physically impossible for the two people who say they saw Frank Rijkaard enter Anders Frisk's dressing room to actually see the door of the dressing room from where they stood," he said.
"We also have a signed statement from Jose Mourinho in which he says he saw Rijkaard go into the dressing room which is contradictary to Chelsea's statement."
Frisk later quit refereeing after receiving death threats from Chelsea supporters and that prompted Volker Roth, the chairman of Uefa's referees' commitee, to call Mourinho "the enemy of football".
Uefa said Chelsea were not to blame over Frisk's sudden retirement but did issue charges over the Blues' late arrival on the pitch for the second half and Mourinho's news conference no-show.
Now the governing body has said: "Uefa today announced the opening of disciplinary proceedings against Chelsea FC, head coach Jose Mourinho, assistant manager Steven Clarke and security responsible Les Miles for making false declarations."
It said that those declarations were "notably in the complaint sent by Chelsea FC following the UEFA Champions League match played against FC Barcelona at the Camp Nou on 23 February 2005.
"By further disseminating these wrong and unfounded statements, Chelsea FC allowed its technical staff to deliberately create a poisoned and negative ambience amongst the teams and to put pressure on the refereeing officials."
Uefa's Control and Disciplinary Body will hear Chelsea's case on 31 March.
Its powers include everything from warning or fining Chelsea, to ruling the annulment of the result of the game in question or throwing the Blues out of the Champions League.