An international rights group says a media code proposed by Sri Lanka's government could have a severe and chilling effect on free speech in the country.

The New York-based Human Rights Watch says the code is "unnecessary and invariably infringe upon the right to free expression."

The group's asia director Brad Adams says the code "is part of a sustained campaign to control the media and curtail dissent."

Media Minister Keheliya Rambukwella rejected the allegation Wednesday, saying the proposed code is "purely voluntary" and "is not a piece of legislation."

The code touches on everything from what news should not be published to how to issue corrections to advertising. Local media groups say if there is to be a code it should be drafted by journalists, not the government.