A host of ill-defined laws has been used in Myanmar to exert control over independent journalism across the country, including in Kachin, Shan and Rakhine states, a UN human rights report on freedom of expression in the country has found.

The report states that it has become "impossible for journalists to do their job without fear or favour."

UN High Commissioner for Human Rights Michelle Bachelet said the report laid bare the perilous position of independent journalists in Myanmar, according to a message UNB received from Geneva on Tuesday.

"Where journalists are jailed for merely visiting an area controlled by an armed group, when their sources are jailed for providing information from conflict zones, and where a Facebook post can result in criminal defamation accusations - such an environment is hardly conducive to a democratic transition," she said.

She called on the authorities to cease the legal and judicial harassment of journalists and to initiate a review of ill-defined laws that facilitate attacks on the legitimate exercise of freedom of expression.

While the conviction last week of two Reuters journalists, Kyaw Soe Oo and Thet Oo Maung, was a particularly outrageous and high-profile example of judicial harassment against the media in Myanmar, the report details a number of other examples of detentions and prosecutions of journalists and their sources indicative of wider trends of suppression of freedom of expression.

Laws on telecommunications, official secrets, unlawful associations, electronic transactions and even import-export and aircraft acts have been used against journalists in a number of cases over the years, the report states.

In one case, three journalists were among seven men arrested in June 2017 for covering an event to mark the International Day against Drug Abuse and Illicit Trafficking in an area under the control of the Ta'ang National Liberation Army (TNLA) in northern Shan state.

Even though the journalists from The Democratic Voice of Burma and The Irrawady were covering a "drug burning" ceremony unrelated to the armed conflict, they were charged under the Unlawful Associations Act, which is "routinely used to allege that any contact with an ethnic armed group is tantamount to a criminal offence."

The case against Swe Win, editor of the online newspaper Myanmar Now, involved a Facebook post in which he quoted a senior monk as saying that high-profile nationalist month Wirathu had violated the tenets of Buddhism. One of Wirathu's followers filed a complaint against Swe Win under the Telecommunications Law in March 2017.

The case is still pending.

Swe Win told the UN Human Rights Office that the drawn-out proceedings in the case, which have included more than 30 court appearances, have undermined his ability to do his job.

In the case of the arrest and prosecutions in 2017 of a documentary crew working for Turkish state television, the Import-Export Law 2012 was invoked in relation to their use of a drone to film the parliament building in the capital city of Nay Pyi Taw.

The charges were eventually dropped but the report states that this case illustrates the "any means to an end" approach of the authorities who will use any available legal provision to deter independent reporting on critical issues in Myanmar - in "flagrant violation of the right to freedom of expression."

The report also refers to "the instrumentalization of the law and of the courts by the Government and military in what constitutes a political campaign against independent journalism," and the "failure of the judiciary to uphold the fair trial rights of those targeted."