Annociate Nimpagaritse, 25, fears she will be killed if she does return to the African state, rated as the fifth most dangerous in the world.

She claimed asylum when she arrived in the UK in August 2005 and began making a new life in Sheffield, studying English and singing in a church choir.

She also began a relationship with a fellow Burundian who has won refugee status, and had just received Home Office permission to marry him when she was arrested in a police raid on a house in the Burngreave area of Sheffield on Friday.

She was taken to a detention centre in Scotland and has been told she will be taken back to Burundi on September 25.

She was previously threatened with deportation in March but was refused entry to the country when she was flown back there, forcing UK authorities to fly her back again.

Miss Nimpagaritse, whose parents were killed by a rebel group fears she will suffer the same fate if forced to return. She said: "I am so fearful of this situation.

"I have been told I am going back and I don't know what to do. It's not safe."

Friends of Miss Nimpagaritse are lobbying Ministers to keep her in England. Liberal Democrat leader and Sheffield Hallam MP Nick Clegg is among more than 1,200 people who have signed a petition.

Campaign spokesman Graham Wroe said: "The case of Annociate Nimpagaritse is an extreme example of a vulnerable young woman who has been tragically and wrongly disbelieved when she presented her appeal for refuge in this country.

"Worse, the Home Office admit they do not monitor what happens to people after they have been forcibly returned to the authorities from which they have fled."

A spokesman for the UK Borders Agency said it did not comment on individual cases.

However, he added: "The Government has made it clear it will take a robust approach to removing those who have no right to be here and last year we removed one person every eight minutes.

"Our asylum decisions are humane and compassionate and are also subject to independent scrutiny by the judiciary."