The arrest comes amid simmering political tensions in Malaysia, with opposition leader Anwar Ibrahim saying he plans to unseat the coalition government that has ruled Malaysia for the past half century.
Anwar had vowed to take power on September 16, with the support of at least 30 government members of parliament.
But on Friday his party said the attempt had been delayed by the government sending 46 MPs on a trip to Taiwan.
|Prime Minister Abdullah Badawi is facing growing pressure to resign [AFP]
Raja Petra's arrest comes a day after a block on his Malaysia Today
blog, popular for its sensational political postings and vibrant discourses, was lifted after two weeks.
The cabinet on Thursday ordered the Malaysian Communications and Multimedia Commission, the government's industry regulator, to re¬instate access to all blocked websites.
Government leaders have repeatedly accused Raja Petra of spreading malicious falsehoods through his blog, which regularly features stinging comments and numerous claims about alleged wrongdoings by public officials.
The blocking of Malaysia Today, believed to be the first official clampdown on a local website, drew criticism from bloggers and journalists who accused the authorities of seeking to quash dissent.
Some of Malaysia's most popular websites and blogs offer fiercely anti-government commentaries, presenting themselves as an alternative to mainstream media, which are controlled by ruling political parties or closely linked to them.
Raja Petra is already facing charges of sedition and criminal defamation over an article and a sworn statement he made alleging links between the country's deputy prime minister and the murder of a Mongolian model.
The trial is scheduled to begin in October.