UN cultural agency UNESCO has honoured Philippines journalist Maria Ressa with its annual press freedom prize.

A former CNN investigative reporter, Ressa gained prominence as editor-in-chief of news website Rappler, attracting the wrath of Philippine leader Rodrigo Duterte.

UNESCO said she had been involved in many international initiatives to promote press freedom, having been arrested on several occasions "for alleged crimes related to the exercise of her profession". She had also been subject to a sustained campaign of gendered online abuse, threats and harassment, at one point receiving more than 90 hate messages an hour on Facebook.

Jury chair Marilu Mastrogiovanni said her “unerring fight for freedom of expression is an example for many journalists around the world.

"Her case is emblematic of global trends that represent a real threat to press freedom, and therefore to democracy."

The Philippine government has levelled a variety of charges at her in an attempt to shut down Rappler. Most recently she was in court on charges of dodging taxes, while Duterte has branded the website “a fake news outlet”. She says the cases are payback for her criticism of the president's policies including his war on drugs that has killed thousands of people.

She was honoured with WAN-Ifra’a Golden Pen of Freedom award and named Time magazine Person of the Year in 2018.

Last year Ressa was convicted of cyber libel by a Manila court but is free on bail pending an appeal in a case that could see her handed six years in jail.