The head of Syria's national Olympic committee may be banned from attending the London games because of his links to President Bashar Assad.
General Mowaffak Joumaa is expected to be refused entry to the UK because of his connection to the Syrian military, The Guardian reported.
The troubled Middle Eastern state has seen a recent spike in violence by the forces of President Assad's regime.
The Home Office is responsible for carrying out background checks on behalf of the International Olympic Committee (IOC) and advises the committee on whether an applicant is suitable for accreditation.
A statement on the Home Office website says: "Accreditation will also not be recommended where an individual's presence at the Games (or in the UK) would not be conducive to the public good."
The Foreign Office is also involved in exclusion decisions, and sources said particular interest would be shown in visitors from countries where there are human rights abuses. Officials are expected to keep a close eye on Syria.
Foreign Secretary William Hague has compared the recent massacres in Syria to those in Bosnia in the 1990s while Prime Minister David Cameron has condemned the killings as "brutal and sickening".
The Syrian charge d'affaires in London has already been expelled in the wake of mounting condemnation of the attacks.
Visas are still being sought for all of the 11 athletes and 20 officials - including coaches - wanting to attend the games on behalf of Syria, whose regime has been condemned by Britain for its crackdown on opponents.
It is thought that the athletes may receive visas because those of Olympic standard are not required to serve in the armed forces, but there is a question mark against General Joumaa and other officials.
General Joumaa has said he will complain to the International Olympic Committee if his visa is denied.
General Joumaa said: "If anyone was blocked because of their military background, that would be unfair. Anyone who has a military background in Syria, they are an ordinary citizen of this country.
"You have seen how much Syria enjoys security and safety. We are a peaceful country. The Syrian people have love in their hearts for the British people."
Last month Deputy Prime Minister Nick Clegg said that no figures associated with atrocities would be allowed into Britain, under new rules preventing entry by people who are not "conducive to the public good".
However, he would not give assurances on specific individuals.
"As far as we are concerned we have recently said very clearly - if you have abused human rights and that is shown to be the case, you can't come into this country," he said.
Asked whether anybody connected to the atrocities in Syria would be blocked from coming for the Olympics, he said: "Of course, what I can't tell you is exactly who those names are."
The decisions on the Syrians are thought to be imminent and showjumper Ahmed Hamsho, 18, is expected to be allowed to compete, The Guardian said.
Hamsho, who has close family ties to the regime of Mr Assad, is the first ever Syrian equestrian to qualify for the Olympics.
A Home Office spokesman said: "We are undertaking stringent checks on all those seeking accreditation.
"This rigorous process has been designed to ensure those working at the Games are fit to do so. We will leave nothing to chance in our aim to deliver a safe and secure Games that London, the UK and the whole world will enjoy."