The report entitled "Zimbabwe: human rights in crisis" was released last Friday to rebut claims by the government to the African Commission on Human and People's Rights (ACHPR) that Harare was compliant with the African charter on human rights.
Article 19, Human Rights Watch and Redress are the other groups that helped write the report.
The report traces the rise in human rights violations and political violence in Zimbabwe to 1999 when the main opposition Movement for Democratic Change (MDC) party emerged as the most dangerous threat yet to Mugabe's stranglehold on power.
Mugabe's government has since the birth of the MDC under popular trade unionist Morgan Tsvangirai pursued every measure possible to block a possible change of government through the democratic process.
They have shut down independent newspapers and clamped down on other voices of dissension while also ignoring court orders in their bid to stifle the democratic process, the reports says.
"The Zimbabwean government has ignored clear directives from the Supreme Court to restore respect for the right of freedom of expression and has harassed and persecuted individuals who dare to speak out," the report reads in part.
The report catalogues in detail how the integrity and impartiality of the legal profession and judicial process in Zimbabwe have been severely compromised over the years through persistent harassment and intimidation of judges and lawyers by state agents or officials.
It says the attacks against lawyers and judges have greatly undermined the authority of the courts and severely limited the access Zimbabwean citizens have to the justice system.
Zimbabwe Justice Minister Patrick Chinamasa was not immediately available to respond or comment on the report.