Britain has refused to grant the head of the Syrian Olympic Committee a visa to travel to London for the Games, the BBC reported on Friday.
General Mowaffak Joumaa's application was refused due to his links to the regime of Syrian President Bashar al-Assad, which has launched a bloody crackdown on protests, said the BBC.
The Home Office interior ministry, which deals with visa applications, and the Foreign Office, both refused to comment when contacted by AFP, saying they "do not discuss individual cases".
The Guardian newspaper said Joumaa submitted his application at the end of last week and it had been turned down.
The decision was made at a meeting of officials from the Home Office, the Foreign Office and the Department of Culture, Media and Sport, the BBC and The Guardian said.
The International Olympic Committee, which was officially responsible for inviting Joumaa to attend the Games, was set to ratify Britain's decision, according to the BBC.
But an IOC spokesman said the body had not yet been approached.
"At this stage that we have not yet received any official approach on this issue and it would be premature to comment on any individual cases," the spokesman said.
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British ministers had already warned that Joumaa could have his visa refused for the Olympics, which begin on July 27.
"We would have to talk to the IOC but yes, of course we can (block his attendance)," sports minister Hugh Robertson said in May.
"We will have to see when his application comes through. We have the power to refuse anybody a visa."
Joumaa is not on a European Union list of Syrian officials banned from travelling to the bloc.
He told The Times newspaper last month that he was determined to attend the Games.
Prime Minister David Cameron has said that Syrian athletes are welcome to attend the Games.
Britain has already expelled Syria's top diplomat in London in protest at the regime's actions, although it has stopped short of severing diplomatic relations.
More than 15,000 people have been killed since the revolt against Assad's rule erupted in March last year, according to rights groups.