Malaysia is considering imposing an Internet filter to block "undesirable" websites, on the grounds of maintaining racial harmony in the multicultural nation, a senior official said Thursday.

The move was quickly condemned by the opposition which described it as a "horror of horrors" that would destroy the relative freedom of the Internet in Malaysia, where the mainstream press is tightly controlled.

A senior official with the National Security Council (NSC) confirmed reports that the coalition government was considering imposing controls -- effectively scrapping a 1996 guarantee that it would not censor the Internet.

"It is to keep out pornographic materials and bloggers who inflame racial sentiments. We need to maintain racial harmony. We cannot have full-blown democracy like in the United States," he told AFP.

"This country must survive," said the official who spoke on condition of anonymity.

The memory of bloody racial 1969 racial riots is still strong in Malaysia, and the need to preserve peace between majority Muslim Malays, and minority ethnic Chinese and Indians, is commonly invoked by the government.

The NSC official dismissed suggestions that the proposal echoed China's aborted "Green Dam" project, a plan to introduce Internet filtering software on all new computers sold in the country.

"It is not like China's Green Dam nor is it a plan sparked by last weekend's anti-government street protests," he said, referring to a massive opposition-led rally against laws that allow for detention without trial.

Malaysia's lively blogosphere has been a thorn in the side of the Barisan Nasional government, which was been in power for more than half a century but was dealt its worst ever results in elections a year ago.

Internet news portals and blogs, which escape tight controls on the mainstream media, were credited as a key element in the swing towards the opposition which has been adept at using new media to communicate its ideas.

Veteran opposition legislator Lim Kit Siang, himself an avid blogger, condemned the proposed controls and urged government legislators to uphold the pledge of Internet freedom.

"(The plan) will be seen as a turn away from an open society and retreat to a closed society with all the grave long-term political, economic and nation-building implications," he said.

The NSC official said that a tender was out for companies to help the Malaysian Communications and Multimedia Commission evaluate an Internet filter.

The "Green Dam" regulation was to be implemented in China on July 1, but widespread opposition both in and outside of China resulted in Beijing backing down.

Beijing had said the Chinese-made Green Dam software would filter out pornography, protecting young people within the world's largest online population.

But trade and rights groups expressed fears that it was another attempt by China to control access to the Internet.