"In sickening statements, draconian laws
, conflicts of interest, and even the use of physical violence, democratic governments are trampling on a freedom that should, in principle, be one of their leading performance indicators," said the group, also known by its French acronym, RSF (Reporters Sans Frontières).
RSF's annual index of 180 countries
ranked Norway, Sweden, Finland, Denmark and the Netherlands at the top for press freedom, with China, Syria, Turkmenistan, Eritrea and finally authoritarian North Korea at the bottom of the list.
The latest index "reflects a world in which attacks on the media have become commonplace and strongmen are on the rise," the group said, and highlighted the decline of press freedom in democracies as a potential "tipping point."
"The democracies that have traditionally regarded media freedom as one of the foundations on which they are built must continue to be a model for the rest of the world, and not the opposite," RSF Secretary-General Christophe Deloire said in a statement.
"If media freedom is not secure, then none of the other freedoms can be guaranteed."
RSF said its global indicator had never been so high, "which means that media freedom is under threat now more than ever."
The decline in media freedom was most visible in European democracies, it said. While Europe still had the lowest level of media freedom violations, the number of infractions had risen by 17.5% in five years, RSF found. In comparison, the Middle East and North Africa -- ranked worst for violations -- deteriorated 4.2% over the same period.
Finland lost its top place for the first time in six years after RSF said Prime Minister Juha Sipila had pressured public TV broadcaster
YLE not to run stories accusing him of conflicts of interest.
An "obsession" with surveillance and violations of the right to the confidentiality of sources had contributed to the decline of the US, UK, Chile and New Zealand in the rankings, RSF said.
"By eroding this fundamental freedom on the grounds of protecting their citizens, the democracies are in danger of losing their souls," said Deloire.
New US President
Meanwhile, RSF said Donald Trump's rise in the US and Britain's Brexit campaign had been marked by "a highly toxic anti-media discourse that drove the world into a new era of post-truth, disinformation, and fake news."
"The hate speech used by the new boss in the White House and his accusations of lying also helped to disinhibit attacks on the media almost everywhere in the world, including in democratic countries," it said.
The watchdog said that nothing seemed to be checking the fall of democracies, in an age of "post-truth, propaganda, and the suppression of freedoms."
The World Press Freedom Index measures media freedom using
an online questionnaire sent to journalists, lawyers and researchers, combined with data on abuse and acts of violence against journalists.
The 2017 index covers the period between January 1 and December 31, 2016.