A judge in London has ruled that five Rwandan men accused of taking part in the country's 1994 genocide should not be extradited to face trial.
They were held in the UK in 2013 after an extradition request from the Rwandan government and denied involvement.
District judge Emma Arbuthnot at Westminster Magistrates' Court said there was a real risk they would not get a fair trial in Rwanda.
The Crown Prosecution Service indicated it would appeal against the ruling.
Vincent Brown, also known as Vincent Bajinya, Charles Munyaneza, Emmanuel Nteziryayo, Celestin Ugirashebuja and Celestin Mutabaruka were accused of playing an active part in the killings.
An estimated 800,000 Rwandans, mostly Tutsis but including some moderate Hutus, died between April and May 1994.
An attempt to extradite four of the men, who are all of Hutu ethnicity, was thrown out by the High Court in 2009 on similar grounds.
The new judgement brought applause from friends and family of the men in the public gallery.
The men have undergone a series of legal hearings during which their defence lawyers argued their lives would be in danger if they were returned.
They face charges including genocide, crimes against humanity, premeditated murder, and participation in acts of devastation, massacres and looting.
The Rwandan government has given assurances they would not face the death penalty.
In the latest ruling, the judge said: "From the evidence I heard and read I have no doubt at all that the overall picture of Rwanda is of an authoritarian repressive state that is not less so than it was and is probably more so than in 2008-9, a state that is stifling opposition in a number of ways.
"There is evidence that the state is suspected of threatening and killing those it considers to be its opponents or they simply disappear at home and abroad.
"There is evidence that suspects can be tortured in secret camps where basic human rights are ignored."
She said she did not the find the extradition requests were compatible with the Human Rights Act 1998.