Chelsea insist that they are unaware of any death threats made to referee Tom Henning Ovrebo after the Norwegian's controversial handling of their Champions League semi-final second leg clash with Barcelona.

Former referee Graham Poll has also revealed that Ovrebo had to be smuggled out of the country after failing to award Chelsea a penalty during the Blues' defeat on away goals.

Ovrebo turned down four penalty appeals as Barcelona won through to a Final against Manchester United later this month thanks to Andres Iniesta's stoppage-time goal.

After the game, Didier Drogba , Michael Ballack, John Terry and Frank Lampard all confronted the official with the Ivory Coast international being particularly vocal in his protests.

A statement on the club's official website read: "Following media reports claiming threats have been made against the referee of last night's game, Chelsea Football Club would like to make clear that it condemns any form of threat against players, officials or supporters.

"If provided with proper evidence Chelsea will take the strongest action against any season ticket holders or members who have participated in this activity.

"Everybody connected with Chelsea is very disappointed with the events of last night.

"However we would stress that we have received no evidence that Chelsea fans are involved in any of the alleged threats reported.

"As a result of these reports we have also been in contact with the police who likewise had not received any complaints."

Poll had earlier said: "This morning he's (Ovrebo) being smuggled out of our country under police escort. This is a referee of a football match, it's a disgrace.

"They had to change the hotel he was staying at because of the fear that maybe fans would find him."

An Oslo police spokesman added: "We are watching closely what is being posted on the internet. Anything we believe would threaten his personal safety will be taken seriously."