Ho Chi Minh City Police have arrested 53-year-old Pham Chi Dung and charged him with “conducting anti-state propaganda” under Article 117 of Vietnam’s Criminal Code.
Police accused Pham of writing anti-state articles and cooperating with foreign media, to deliver “distorted information”.
Pham has been a weekly contributing journalist for SBS Vietnamese for the past three years.
He is also a contributor for the Voice of America and the BBC, under several different pen names, according to human rights group Defend the Defenders.
He is expected to remain in detention for the next four months as police investigate and faces seven to 12 years if convicted.

Phạm Chí Dũng Source: Supplied
He was previously arrested in 2012 on the same charge but released six months later without trial.
Pham was a founding member of the Independent Journalists Association of Vietnam (IJAVN) in 2014.
Nguyen Tuong Thuy, vice president of IJAVN told SBS Vietnamese: “On this matter of the arrest of Mr Pham Chi Dung, we strongly oppose it to the authority. They alleged he violated Article 117 relating to any propaganda against the Vietnam government, but for me, I think all of his writings prove freedom of speech and freedom of media to express his ideas peacefully which has been respected in the Vietnamese constitution, as well as in many international conventions.
“I have read most of his writings and I have a conclusion that he has always been so careful and his power in writing was so immense. We, all members of Independent Journalists in Vietnam are surprised at the news of his arrest and it just a warning to those who have ideas of independence and democracy for Vietnam," Thuy added.
In 2014, Pham was listed among the world’s information heroes of Reporters Without Borders.