A High Court judge has ordered a halt to sending failed asylum seekers back to the Democratic Republic of Congo.
A hearing next month will decide whether DR Congo is safe enough
In a major defeat for the Home Office, Mr Justice Collins said no-one should be removed until the African country's safety record was reviewed by experts.
The judge heard evidence that others deported by the UK were raped and tortured once back in DR Congo.
The Home Office's counsel said such claims were exaggerated and there was strong evidence the country was safe.
The action was bought by 10 failed asylum seekers after Home Secretary Jacqui Smith refused to halt a charter flight to DR Congo on 30 August.
Christopher Jacobs, representing them, argued they should not be sent back until a hearing in September decided whether the country was fit for returning asylum seekers.
He said the Asylum and Immigration Tribunal (AIT) would hear evidence from former DR Congo immigration officers and security staff of what happened to some of those on an earlier chartered flight in February.
In his ruling, Mr Justice Collins said: "I don't consider it would be reasonable for the Secretary of State to take the attitude that she can continue to remove."
He asked Lisa Bush, for the home secretary, whether the home secretary herself had "completely reliable" evidence that there was no risk.
Miss Bush said there was "no realistic possibility" that those returned faced a risk.
'Playing with lives'
The judge said: "Difficult decisions have to be made. But you are playing with people's lives and if you get it wrong the decision may affect whether a person lives or dies or whether they are dealt with in an appalling fashion."
He also referred to a similar ongoing unresolved case involving Zimbabwean failed asylum seekers, in which the Home Office has also been accused of attempting to deport people without being sure of the situation they would be returning to.
In that 2005 challenge, campaigners argued that reports relied upon by the Home Office were unreliable and those deported to Zimbabwe were at risk of persecution and torture.
Mr Justice Collins concluded by saying a new ruling by the AIT, due to take place next month, should decide whether DR Congo was a safe place to return asylum seekers.