The report, set for release on April 27, bases its index on threats of jail terms against journalists, internet restrictions and overall repression in each nation. Eritrea topped the list, according to the report, which explains that even journalists for state-owned news outlets fear arrest in the Horn of Africa country.
In Myanmar, news media are under tight government control, despite an end to more than four decades of pre-publication censorship in 2012, the report states. Laws and regulations have since been designed to restrict journalistic freedom and old laws are also being employed, it says.
The Printers and Publishers Registration enacted in March 2014 bans news that could be considered insulting to religion or disruptive to the rule of law or the nation's unity.
Also, the Official Secrets Act of 1923 and other national security-related laws are threatening the imprisonment of journalists who report on military matters. Journalists are barred from reporting the military side of conflicts with ethnic groups.
The report noted that freelance reporter Par Gyi was shot to death by the military in October 2014 near Myanmar-Thai border.
The report lists the worst offenders in order as Eritrea, North Korea, Saudi Arabia, Ethiopia, Azerbaijan, Vietnam, Iran, China, Myanmar and Cuba. The CPJ is an independent, non-profit New York-based organisation that promotes global press freedom.