"Some years ago I met an individual who had intercourse with someone they met online, who didn't disclose that they had an STD," or sexually transmitted disease, Gonzalo Paternoster of Florida-based SSP BioAnalytics said ahead of the launch of the Safe Sex Passport on December 1, World AIDS Day.

"The idea popped into my head that people know but don't tell the truth, and we needed an independent way to verify someone's health status," he said.

The Safe Sex Passport will be available – at a cost – to anyone over the age of 18 who goes online and orders the credit-card-size article.

"As soon as you order your card, you are referred to an affiliated laboratory where you can get tested for five major STDs," Paternoster said.

Card holders are tested for HIV, genital herpes, Chlamydia, gonorrhoea and syphilis. "When you go to the test facility, you will have to show your official ID to make sure you are the person who owns the safe sex passport. "The test results are tied to the card. So let's say now you meet someone: they can call a phone number and get the test results and test date for you, plus identification information so that they know for sure that you are really the person who was tested," he said.

"In the old days, you had to take someone's word for it when they said they had been tested and were in the clear. Now you can ask for proof."

Subscribers will also be provided with virtual health certificates, which can be posted on their online dating or MySpace profile page.

Nearly 15 000 people and several dating websites have already expressed an interest in the safe sex passports and online health certificates, Paternoster said. The biggest age group showing an interest in acquiring the card are 27- to 47-year-olds, he said.

"A lot of them are divorced or have broken up after a long-term relationship, and now they're back in the dating world and they're terrified."

Sixty percent of inquiries have come from Europe, where the passport and health certificates are expected to be brought to market early next year, Paternoster said. "The system will probably be available in the first quarter of 2008 in the UK and France to begin with," he said.

"As fast as we can translate the website and documents, that's how fast we'll be able to launch around Europe," he added. Europeans will pay only for the card, which costs around $75 to $100, whereas US users will have to pay for the STD tests, too.

"Some people argue this system will allow more sexual freedom, but it's actually going to make people behave more responsibly, be tested, seek treatment and tell their partner if they have an STD," Paternoster said.