The United Kingdom's Home Department inspected the backgrounds of up to 500,000 in an extraordinary security screening designed to stop the Olympic Games being disrupted by criminals or terrorists, security reports indicated.
The 500,000 figure includes anyone seeking employment at the Games, as well as athletes, coaches, and officials from more than 200 competing nations, London-based Guardian Newspaper reported in Wednesday's issue.
In what is understood to be the biggest inspection process since World War II, the Home Office has so far refused about 100 applications for Games accreditation, mostly because of concerns about the extent of people's criminal records, the daily added.
However, some people have been denied accreditation on the advice of the national security service MI5, which has to assess whether a person might pose a significant threat to national security, it said.
"We have been told the threshold for refusing accreditation has been set high, which means some of those working at the Olympics this summer will have 'come to the notice of' the police or MI5 in the past. To be rejected, they have to pose a significant potential threat to the safety of the Games," the newspaper quoted a source as saying.
Police and MI5 have been taking a careful look at all those who may end up working at the Olympic sites. It is an obvious way for would-be terrorists to gain access to venues, and police are aware that terrorists may masquerade as casual workers looking for temporary jobs, the newspaper added.
However, those involved in the security of the Games say they have found no evidence so far that Al-Qaeda supporters have tried to infiltrate the civilian workforce, the daily said.
The security authorities are conducting a security evaluation of a number of foreign figures willing to attend the London Olympics opening ceremony, while Syrian Olympic Committee President Mowaffak Joumaa is not allowed yet to head his country's delegation to London.
Among those still to be inspected are many of the 10,000 security guards who will be employed by G4S, the private firm which is contributing 23,700 personnel at the Olympic venues, it added.