Several competitors have caused security headaches by tweeting high resolution images of their Locog accreditation, just ahead of Friday's opening ceremony.
Their tweeting of high security passes has raised fears that the barcodes, which do not feature infra-red or microchip technology, could be duplicated by fraudsters, the Daily Mail reported.
Threat management firm IPC even believe the carelessly tweeted photos could be a 'golden ticket' into Olympic venues for terrorists.
Organised crime gangs and ticket touts could also gain access to venues by duplicating the official Locog lanyards from Twitter, according to experts.
US women's footballer Carli Lloyd was among the first to give organisers a security headache when she tweeted her accreditation for the Olympic Village.
The American was so excited by the arrival of her official lanyard that she took a snap of her ID before posting it online with a message that read: "All set, ready to go."
British Olympic and triple world champion rower Zac Purchase uploaded a full size version of his accreditation next to a comment complaining about his ID picture.
Visible in the picture was his full barcode and athlete number alongside a breakdown of accessible areas.
As more athletes collected their official accreditation this week, Twitter timelines quickly began to fill up with potentially dangerous pictures of games passes.
It is thought that any fraudster sophisticated enough to copy a photo of the pass could gain access to the Olympic Village, dining areas, the Olympic Park or even the field of play.
One security expert condemned the actions of the athletes saying they could have opened the door for terrorist activity at London 2012.
Will Geddes is the head of threat management firm IPC who have been advising overseas journalists and VIPs ahead of the games.
"What you've got here is a really stupid situation were athletes have been given important security documents and have compromised those documents by showing the information contained to all and sundry," he said.
"As far as I know, there is no electronic element to that passes, they just need to be waved on entry, or at the very most have the barcode scanned. But if you have a good enough picture of a barcode, you can duplicate the information relatively easily," he added.
