Chief executive Tim Lam would not elaborate on the circumstances of the case, only saying that he was served with a court order forcing him to hand over the data.

'This is not something that we have publicised simply because we do not want to make a big issue out of it,' he said. 'Our users should be aware that if they post something illegal on our site and we receive a court order telling us to disclose their information, we will follow the law.'

E-Silkroad has alleged about a dozen libellous messages appeared on IceRed between October last year and March this year, when E-Silkroad listed on the Growth Enterprise Market.

Along with a demand for compensation, E-Silkroad has asked the High Court to force IceRed to reveal the names, addresses, e-mail addresses and Internet Protocol (IP) addresses of the users who sent the messages.

Executives have said they would consider suing any individuals they identified. The official would not say what E-Silkroad has been able to do with the IP address, which could be used to trace the messages back to the computer where they originated.

Because the messages were not sent by a registered user, IceRed does not have any of the other information being sought.

The case has been heard in closed court.

Mr Lam said the main issue remaining in the E-Silkroad case was whether IceRed could be held liable for what its users posted, not whether people had the right to online anonymity.

The revelation that IceRed has released user information is unlikely to be well received by its members.

The E-Silkroad case prompted a heated debate over online freedom of speech, and IceRed supporters have donated HK$50,000 to cover the site's legal fees.

Many people gave money saying they wanted to protect their identities so that they could participate in controversial discussions without fear of retaliation.

'We donated to protect our anonymity, not to make IceRed richer,' said one user.

Mr Lam, and IceRed co-founder Kenny Lam, have promised to update users on the status of the lawsuit, but maintain they cannot say anything until after the case is closed.

At one point, an announcement was posted on the site denying rumours that user information had been disclosed. That notice has since been removed.

Tim Lam said IceRed remained committed to protecting the privacy of its members, pointing out that he received two or three requests for user information every day, all of which were turned down.

'In the case where we released information, the person had clearly broken the law,' he said. 'People still have the impression that the Internet is the wild, wild west, and that they can say whatever they want without being held responsible for it.'

Mr Lam said the controversy had not hurt IceRed's popularity, with page views increased by 30 per cent since March.