KUALA LUMPUR (REUTERS) - Human Rights Watch on Thursday (Oct 13) expressed concern over planned amendments to Malaysian media law that would give broader powers to the authorities to stifle online dissent amid a wider crackdown on free speech and assembly.

The US-based rights group's report comes as Prime Minister Najib Razak battles criticism over his handling of a multi-billion dollar financial scandal at state fund 1Malaysia Development Berhad (1MDB).

"What Malaysia is trying to do is put the Internet genie back in the bottle, back to a time when the government had greater control over information received by its citizens," HRW Asia deputy director Phil Robertson told reporters.

Amendments to the Communications and Multimedia Act have not been publicly disclosed. Media reports have said they could require news portals and political blogs to register with the government, increase penalties for offences under the act and broaden powers for the authorities to take down online content.

The HRW report said a rising number of Malaysians were investigated over the past year for criticising the government. It follows an earlier HRW release last year on the increasing use of criminal laws to stifle dissent.

"We found that there were few countries in South-east Asia worse than Malaysia when it came to the rapid deterioration of human rights... it's like a bad movie sequel," Mr Robertson said.

The prime minister's office did not respond to an e-mailed request for comment.

Communications and Multimedia Minister Salleh Said Keruak said the act would only be enforced against "malicious and harmful content on the prime minister" and safeguard against online abuses related to religion, race, pornography and gambling.

"Action will not be taken without an investigation being carried out first, and only if there is sufficient evidence of a breach of the law," he told Reuters.

Despite a long-standing government pledge not to censor the Internet, authorities have blocked several websites and news portals carrying reports critical of 1MDB and Mr Najib.

Authorities have also cracked down on anti-government rally organisers, opposition leaders and activists.

Among them was artist Fahmi Reza, who faces charges under the act for a caricature of Mr Najib with a clown face.

1MDB is the subject of money-laundering investigations in at least six countries. The US Department of Justice filed lawsuits in July to seize dozens of assets from 1MDB, saying US$3.5 billion (S$4.85 billion) was misappropriated from the fund.

Mr Najib has denied any wrongdoing and said Malaysia will cooperate in the international investigations.