The award-winning head of a Philippine online news site that has aggressively covered President Rodrigo Duterte’s policies has been arrested by government agents in a libel case.

Maria Ressa, who was selected by Time magazine as one of its Persons of the Year last year, was arrested over a libel complaint from a businessman which Amnesty International has condemned as “brazenly politically motivated”.

Mr Duterte’s government said the arrest was a normal step in response to the complaint.

Arrest warrant being served right now vs Rappler CEO Maria Ressa. An officer part of the serving party prohibits Rappler employees from taking photos and videos inside the office.

Posted by Rappler on Wednesday, February 13, 2019

Rappler, the news site which Ms Ressa heads, said National Bureau of Investigation agents served the warrant and she was escorted from the Rappler office to NBI headquarters.

“We are not intimidated. No amount of legal cases, black propaganda and lies can silence Filipino journalists who continue to hold the line,” Ms Ressa said in a statement.

“These legal acrobatics show how far the government will go to silence journalists, including the pettiness of forcing me to spend the night in jail.”

Justice secretary Menardo Guevarra said Ms Ressa was indicted more than a week ago.

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

Time cited Ms Ressa and several other journalists as “guardians” in what it said was an effort to emphasise the importance of reporters’ work in an increasingly hostile world.

Ms Ressa, who has worked with CNN, was also the winner of two prestigious journalism awards last year, a Press Freedom award from the New York-based Committee to Protect Journalists, and the International Centre for Journalists’ Knight International Journalism Award.