Companies and consumers with .biz domain names have been warned to check carefully any unsolicited emails they receive asking them to renew the address.

The emails, sent by a company called Dot Biz Domain Renewal, warn businesses that their .biz domains are due for renewal, and give details of how to pay by credit card on its website at www.domain-renewal.biz.

But .biz domain names do not need to be renewed until November 2003, as they were originally issued for a period of two years in November 2001.

Dot Biz Domain Renewal is also claiming that it is an accredited registrar. But the only body that accredits registrars is the Internet Corporation for Assigned Names and Numbers (Icann) for Top Level Domain names, currently .com, .net and .org.

Dot Biz Domain Renewal does not appear on Icann's list of accredited registrars.

Another major worry is that the company's website does not use the secure https prefix, indicating that credit card details could be hacked.

In addition, the postal address that the company is using in Regent Street, London, uses a non-existent postcode, W1R 7PB.

vnunet.com went to the address and found that, although it was the office address for a number of legitimate companies, there was no sign of Dot Biz Domain Renewal. Security personnel at the building had no knowledge of the company.

But the same address - including the same non-existent postcode - has been used by another company that set itself up as a web hosting firm, Dot Com Avenue, run by a Peter Francis Macrae.

Macrae is currently under investigation for fraud by Cambridgeshire Trading Standards and Cambridgeshire Police and is currently on police bail.

The registrant of the domain-renewal.biz domain name is listed as Mel Goudie, who also owns a company called domainrenewals.biz. Earlier this year that company sent out emails similar to those sent by domain-renewal.biz.

vnunet.com has telephoned and sent emails to Goudie and his company, but to date there has been no response.

The emails sent out by domain-renewal.biz have prompted some web hosting companies, such as Internetters and .biz registry Neulevel, to post warnings on their websites and alert customers by email.

Ken Sorrie, co-founder and director of Internetters, told vnunet.com that domain name owners should be on their guard.

"People should always check out the credentials of the companies sending emails like this," he said.

"Very often such unsolicited domain name renewals appear to come from UK-based addresses, but actually transfer the domain names to another registrar somewhere on the other side of the globe."

Detective Constable Jody Faro, of Cambridgeshire police, who is leading the investigation into Peter Francis Macrae, said that anyone who had any concerns about Dot Com Avenue or Dot Biz Domain Renewal could email him at jody.faro@cambs.pnn.police.uk.