Guy's & St Thomas' Hospital Trust has become the latest target of domain name resellers using high-pressure sales tactics to dupe organisations into buying extra online addresses at premium prices.

Domain Registrar Services (DRS), which has been the subject of numerous complaints, contacted the Trust claiming that a mystery buyer was attempting to register variations of its name.

Susan Pollock, web manager at Guy's, told vnunet.com that three salespeople tried to sell nine domain names to the hospital at a total cost of £1,400, about £1,130 more than the average cost of £30 each to register domain names.

"Three people pursued me saying that someone was trying to register variations on the Guy's Hospital domain name which would direct users to sites with inappropriate material," she said.

"They implied that these were porn sites and that, to stop this happening, I would have to register the names.

"They also said that I could only register the domain names through them. This rang alarm bells as I knew that was a lie, so I checked with a colleague and Internetters, the domain registrar that hosts our current website.

"This makes me so angry. We are a charitable trust with small budgets and we can't go around throwing money away."

However, DRS spokesman David Hayes defended his company's actions, claiming that mystery buyers did buy up domain names.

"Mystery shoppers do exist," he said. "We don't pressurise. All we try and do is advise people what can happen to these domain names. Maybe the people you have talked to have got their wires crossed."

When asked, Hayes did not provide any evidence of mystery shoppers.

Last week vnunet.com forwarded over 70 complaints to the Office of Fair Trading (OFT), almost all against DRS and a Maidstone-based reseller called Anet.

An OFT spokeswoman confirmed that Anet's practices are now being investigated.

"We are further down the line with Anet," she said. "We are aware of DRS and are liasing with Carmarthenshire Trading Standards, but have not launched an official investigation."

Currently, no organisation is responsible for policing the sale of domain names.

The Department of Trade and Industry (DTI) suggested that it is an issue for domain name registry Nominet.

"In the first instance it will be Trading Standards and the OFT to deal with bogus resellers," said a DTI spokesman. "Specifically though it is an issue for Nominet to take forward and we can't comment on its position."

But Nominet has little power to stop the practice, despite such techniques being frowned upon by its legitimate members.

Jennie-Marie Idler, European general manager at domain registrar NeuStar, explained that mis-selling is a huge problem.

"I don't envy Nominet's position," she said. "However, mis-selling can be proven and the government should examine these scams and make an example of these companies."