KUALA LUMPUR (AFP) - One of Malaysia's best-known political cartoonists has been arrested for sedition over a Twitter posting that criticised the jailing of opposition leader Anwar Ibrahim, the artist's wife said on Wednesday.

Mr Zulkifli Anwar Ulhaque - better known as Zunar - was arrested Tuesday night, hours after Anwar was jailed for five years in a politically charged sodomy case. "Of course this is a form of intimidation, with the purpose that society does not question the authorities," his wife Fazlina Rosley told AFP. "Zunar will not bow down to this intimidation. He will continue to criticise even if he remains in jail."

The cartoonist's lawyer Melissa Sasidaran said he is expected to be held for a few days.

Zunar, 52, had suggested in a Twitter post that Malaysia's judiciary - whose independence has been questioned before in political cases - had bowed to the country's authoritarian regime. "Those in the black robes were proud when passing sentence. The rewards from their political masters must be lucrative," the tweet had said.

Prime Minister Najib Razak's government has been condemned at home and abroad for filing a wave of sedition cases against its opponents over the past year, apparently in response to the opposition's growing electoral successes.

Tuesday's Anwar ruling was also criticised by international human rights groups and the United States, which said it raised questions over the rule of law.

Anwar called the ruling a "political conspiracy" to run him out of politics.

Mr Zunar has courted the attention of the authorities in the past through his cartoons, which often take aim at Datuk Seri Najib, his notoriously spendthrift wife Rosmah Mansor, and contentious issues such as Anwar's sodomy trial.

Earlier this month, he said his office was raided by police as part of an apparently separate sedition investigation.

The country's hardline police chief Khalid Abu Bakar said on Twitter on Tuesday that authorities also would investigate two opposition politicians for sedition over tweets critical of the Anwar ruling.

Human Rights Watch, in a statement criticising Mr Zunar's arrest, said Mr Najib's government was "turning peaceful criticism into a criminal act that threatens the state".