Another blogger, Raja Petra Kamaruddin, was detained last week. An opposition blogger has been arrested for allegedly displaying a national flag upside down on his website, as the government comes under more pressure.
Syed Azidi Syed Aziz, better known as Kickdefella, is the second blogger to be arrested in a week.
The Malaysian opposition leader, Anwar Ibrahim, is demanding a vote of no confidence in the government.
Mr Anwar says he now has the support of enough MPs to bring down Prime Minister Abdullah Badawi.
Mr Syed Aziz, picked up late on Wednesday, is being held under the Sedition Act.
He is known as a supporter of the conservative Islamic PAS party, a component in the coalition seeking to topple the government of Prime Minister Abdullah Badawi.
Mr Syed Aziz’s website had recently advocated that people fly the Malaysian flag upside down as a protest against the current political upheaval.
Mr Abdullah reportedly called the protest “a malicious act” and police were told to investigate the campaign.
“We were informed that the police were looking for us on Tuesday and waited for them but they didn’t show up,” his Mr Sayed Aziz’s wife Bariah Ishak told the Star daily newspaper.
“We thought the worst was over but they came looking for him and so he surrendered,” she added.