Olympic stars including Rebecca Addlington, Phillips Idowu and London 2012 silver-medallist Lizzie Armitstead have reportedly fallen victim to 'cybersquatters'.
Dozens of web domains related to Olympic athletes and the Games themselves have apparently been registered by third parties.
Some owners of the domains - registered legally through registration services - are now said to be demanding thousands of pounds to transfer ownership.
Many of the domains were registered months in advance of the competition.
Notably, swimmer Rebecca Adlington's website's .com equivalent (rebeccaadlington.com) has been registered by a person in China, according to the domain's contact information.
WHOIS lists the person in Hebei, China, as its registrant.
A message posted on the site offers the address for sale for £30,000.
"Buy the most value domain for the Great British champion of 2012 London Olympics," it says.
"The domain is her and all British people’s Lucky Goddness
"This domain can bless she get the champion."
According to website registration site Names.co.uk, other athletes who have apparently fallen victim to the practice include:
All of the above websites are offered for sale or are currently displaying adverts.
Names.co.uk said that other websites - including teamgb.co.uk - are for sale.
The .com addresses of both Wenlock and Mandeville, the Olympic mascots, are also apparently being held by cybersquatters.
However it was not possible for the Huffington Post UK to independently check who registered those addresses, and the owners of the sites have not been accused of wrongdoing.
David Emm, senior regional researcher at the security firm Kaspersky, told the Huffington Post UK that the cybersquatting issue had been a long-term problem for Olympic organisers.
"Cybersquatting has been around for quite a long time and it attracts attention when it's something notorious," he said.
"People are trying to hijack an established brand… if they get in there first they can hijack any traffic that would naturally come that way via the name."
Emm said that for the groups or individuals behind cybersquatting, using athletes' names was a less risky bet as they've not as likely to pursue it. He said alongside squatters looking for cash, similar tactics were used by malware developers trying to exploit URLs with built-in traffic.
"From an individual consumer's point of view the key is to make sure it's the URL you're expecting," he said. "Type URLS in yourself - its more of a pain in the neck but you're less likely to fall victim than by clicking on a link."