Maria Ressa, one of Time magazine's Persons of the Year, arrested in Philippines

Philippine authorities have arrested Maria Ressa, head of an online news site that has criticized President Rodrigo Duterte's policies, weeks after she was named one of Time magazine's Persons of the Year.

Journalist heads news site Rappler, which has been critical of president's policies

Philippine journalist Maria Ressa, centre, is surrounded by media as she is escorted by a National Bureau Investigation agent at the NBI headquarters following her arrest in Manila on Wednesday. (Ted Aljibe/AFP/Getty Images)

Philippine authorities have arrested the head of an online news site that has criticized the president's policies.

Maria Ressa, selected in December by Time magazine as one of its 2018 Persons of the Year, was arrested over a libel complaint that Amnesty International has condemned as "brazenly politically motivated."

President Rodrigo Duterte's government says it was a normal step in response to a private complaint.

The complaint centres on a 2012 article that linked a businessman to murder and trafficking of humans and drugs, citing information contained in an intelligence report from an unspecified agency, Reuters reported.

National Bureau of Investigation agents served the warrant Wednesday afternoon and she was escorted to NBI headquarters, according to Rappler Inc., the news site headed by Ressa.

Ressa was indicted more than a week ago, said Justice Secretary Menardo Guevarra.

Rappler is one of several news agencies deemed critical of Duterte's policies, including his anti-drug campaign that has left thousands of suspects dead.

The Committee to Protect Journalists called the charge against Ressa "spurious."

Duterte has called Rappler a "fake news outlet," and even suggested it might be linked to the U.S. Central Intelligence Agency.

The National Union of Journalists of the Philippines called Ressa's arrest "a shameless act of persecution by a bully government."

With files from CBC News and Reuters