KUALA LUMPUR - A MALAYSIAN court is to free a blogger who was detained under the country's draconian security laws and whose arrest in September sparked condemnation from rights groups, state news agency Bernama reported on Friday.

Opposition supporter Raja Petra Kamaruddin, 58, was imprisoned under Malaysia's Internal Security Act that allows indefinite detention without trial.

He was charged with being a threat to security for insulting Islam in this mainly Muslim country of 27 million people.

The blogger is due in court later on Friday and will be freed after a court accepted his lawyer's plea saying his arrest was illegal, Bernama said.

Raja Petra's blog has been a thorn in the side of Malaysia's government, especially for Deputy Prime Minister Najib Razak.

The blogger is being tried in a separate court on sedition charges for linking Mr Najib, who will become prime minister in March, to the gruesome murder of a Mongolian model.

The model, Altantuya Shaariibuu, was shot in the head twice and her body blown up with explosives in a jungle outside the Malaysian capital in October 2006.

Mr Najib has strongly denied the blogger's accusations, terming them 'total lies'. The issue has not halted his rise to the top of Malaysia's ruling party and he will be elected unopposed at party polls in March.

The United Malays National Organisation leads a coalition that has ruled this south-east Asian nation for 51 years but which stumbled to its worst ever election result in March when it lost its two-thirds majority. -- REUTERS