Bangkok, Nov 27 (IANS): Human rights NGO Amnesty International urged Malaysia on Sunday to free a popular political cartoonist who has been arrested over making offensive drawings of Prime Minister Najib Razak.

Zulkiflee Anwar Ulhaque, or Zunar as he is also known, was arrested for sedition on Saturday, a day after security forces dismantled his exhibition showcasing drawings of the Prime Minister that were considered offensive, Efe news agency reported.

"The arrest of Zunar is an outrage. The charge of sedition against him must be dropped immediately and he must be unconditionally released from detention," AI's Deputy Director for Southeast Asia and the Pacific Josef Benedict said in a statement.

Benedict accused the Malaysian authorities of using repressive laws to "silence and punish peaceful voices under the guise of national security".

The campaign against Razak, who assumed office in 2009, gained momentum in 2015 when he was accused by foreign media of having siphoned off nearly $700 million from government fund 1MDB (1Malaysia Development Berhad).

Razak and his supporters denied the accusations and the Malaysian public prosecutor's office exonerated him of all charges in January 2016 after an investigation by the anti-corruption agency.