The Singapore government recently indicated a willingness to loosen restrictions on freedom of speech, but pointed to the Internet as a potentially destabilising force.

Tan Chong Kee, Web editor of Sintercom.org, received a letter from the Singapore Broadcasting Authority asking him to register within 14 days as a site that "engaged in the propagation, promotion or discussion of political issues relating to Singapore on the Internet".

Cecilia Yip, spokesperson for the broadcasting authority, confirmed the letter was sent to Mr Tan but gave no further details. A registration form attached to the letter instructed Sintercom to accept full responsibility for its content once registered, Mr Tan said.

"Perhaps the fact that people wonder if they are being watched will cause some to stop or modify their views," Mr Tan said when asked how registration might affect the forum's discussions. "Perhaps the reverse might happen to others. Perhaps there is no effect at all."

Five years ago, Sintercom's editors appealed successfully for exemption from registration. A 1996 letter from the Singapore Broadcasting Authority said authorities believed Sintercom's editors would "exercise responsibility, intelligence and maturity in its selection of postings".

Mr Tan said he wrote to broadcast officials to ask if anything had changed that made registration necessary now, but there had been no reply.