Hiddink fumes at Norwegian referee's display
Chelsea manager Guus Hiddink said it would be impossible to prove claims UEFA did not want an all-English Champions League final.
The London side were furious about a number of what they saw as clear penalties which were not given by referee Tom Ovrebo as Barcelona progressed on away goals thanks to a 1-1 draw at Stamford Bridge achieved with an injury-time leveller by Andres Iniesta.
According to Sky Sports, some of the Chelsea players were speculating afterwards that UEFA wanted to avoid a repeat of last year's all-Premier League final.
However Hiddink was careful not to be drawn on the claims, saying: ''Conspiracy is a very tough word and, if there is, you have to prove it.
''Obviously there is a lot written and said prior to this game. I can only mention what I see. I cannot say whether UEFA wouldn't like another English final.''
He added: ``They (referees) are human as well and everyone can be influenced by certain singing around, that could be possible. These are all half accusations. It's difficult to have a right opinion about that.''
Chelsea dominated the semi-final second leg and seemed to destined to seal a date with Manchester United for the second year running after Michael Essien's wonder strike, particularly when Eric Abidal was dismissed for a challenge on Nicolas Anelka.
But the referee denied Chelsea a number of spot-kicks for perceived offences including a shirt pull on Didier Drogba and handballs by Gerard Pique and Samuel Eto'o.
Hiddink said: "We are so disappointed because there are two issues. One is that we could have and should have scored in some open situations and because we talk a lot about the not given penalties. Didier's shirt-pulling is okay, we had [Thierry] Henry's situation in Barcelona, okay. But there were three other situations that were so clear. I shall not say what we really feel but it's injustice.
"It's not just that you can be mistaken. It's difficult, for instance, for the red card of Abidal on Anelka - difficult because, I think, Anelka was through, he touched with his left leg Anelka. You can discuss these situations for a referee.
"But if you have seen clearly and he was five yards [away], if you have seen clearly the ball on Pique... If he was blocked there is also an assistant referee. There's one I think with the shot on Eto'o and he's turning around and you have to have your arms down. Those two situations make you think.''
He continued: "The [Florent] Malouda situation in the first half when they were struggling a bit. They go in the box, [the referee] had a perfect view, and he was grabbed inside the box.
"That's also a penalty, which means there were three, four clear situations, not just one doubtful as the Henry situation was in Barcelona, let's be honest. Nevertheless, we should have scored in other situations as well. Whether people don't like an all-English final or not, we should have scored also.''
There were ugly scenes in stoppage time and at the final whistle as players including Michael Ballack and Drogba confronted the referee.
The Ivory Coast forward also swore audibly on television as he screamed at the camera the situation was a "disgrace''.
But Hiddink vowed to stand by his players, saying: "I can fully understand in the emotion of the game, as long as they don't touch him, I can fully understand this disappointment. It's not just one decision in doubt but it's several not made decisions.
"I can fully understand and I protect my players for this when they have this emotion, just with loads of energy and adrenaline in their bodies.''
Chelsea striker Didier Drogba was furious after the game and labelled referee Tom Henning Ovrebo a "disgrace''.
The Ivory Coast frontman, who was unhappy after being subbed in 72nd minute, approached the referee after the game.
He then turned to the television camera, shouting that the official was a "f****** disgrace''.
Chelsea fans also threw flags at the officials and the Barcelona bench.
In the Champions League final last season against Manchester United, Drogba was sent off for raising his hands to Nemanja Vidic.