Amnesty International claim that Brazil’s military police have been responsible for the deaths of over 1,000 people in Rio de Janeiro between 2010 and 2013.
The damning report comes a year before Rio hosts the Olympic Games in 2016.
According to figures released by Amnesty 16 percent of killings in the city over the past five years were perpetrated by on-duty officers.
Authorities say officers regularly come under fire from drug gangs that occupy the city’s favelas.
The police union Sindpol stated that 114 police have been killed in 2014 alone.
Amnesty claims that the civilian deaths were often illegal with people being killed after being wounded or in police detention.
It added that those responsible often escape justice.
The prosecutor’s office in Rio says that 587 police officers have been investigated and brought to justice over the past five years.