In this still image made from video provided by Al Fajer, a Sudanese NGO, Mariam Yahya Ibrahim is seen sitting next to Martin, her 18-month-old son, while holding her baby girl at a prison in Khartoum. File picture: Al Fajer, via AP

Khartoum - The husband of a Sudanese Christian woman facing threats after her apostasy death sentence was overturned expressed relief on Friday that the family has been given refuge at the US embassy.

“Really, it's good,” Daniel Wani, the American husband of Mariam Yahya Ibrahim, 26, told AFP by telephone, adding that embassy staff have been “very helpful and very nice”.

He said his wife and two children, who could be heard in the background, are doing well at the heavily-guarded facility on the outskirts of Khartoum.

The couple's baby daughter was born in prison shortly after Mariam was sentenced to death.

Wani confirmed that they have sought the embassy's protection because of death threats against his wife.

In Washington, State Department spokeswoman Marie Harf said Mariam and her family were “in a safe location” and Sudan's government “has assured us of the family's continued safety”.

Citing privacy considerations, she declined to specify further the location of Mariam, whose arrest - and potential execution - raised deep concern among Western governments and human rights activists.

One of Mariam’s lawyers, Mohanad Mostafa, told AFP late on Thursday that the family had gone to the US mission after her release from a police station where she had been held since security agents stopped them from travelling to the United States on Tuesday.

The family think the embassy “is a safe place for them”, Mostafa said.

Mariam is charged with forgery and providing false information in relation to a South Sudanese travel document she used to try to leave the country, a day after an appeal court overturned her apostasy conviction and released her from prison.

Following her release, she immediately went into hiding at another location because of the threats to her life.

Christian activists say her “alleged brother” stated that the family would carry out the death sentence if she were acquitted.

Mariam was born to a Muslim father and an Ethiopian Orthodox Christian mother.

Her father abandoned the family when Mariam was five, leaving her to be raised by her mother, according to the Roman Catholic Archdiocese of Khartoum, which said she joined the Catholic church shortly before she married.

On May 15, a court convicted Mariam under Islamic sharia law that has been in force in Sudan since 1983 and outlaws conversions on pain of death.

Sudanese government officials could not be immediately reached to comment on the family's decision to seek safety at the embassy.

Khartoum on Wednesday summoned the charges d'affaires of Washington and Juba over Mariam's travel documents.

Sudan's foreign ministry criticised South Sudan's issuing of the travel permit, “despite their knowledge that she is a Sudanese national”, while condemning the US for trying to help the woman leave Sudan “via illegal (false) travel document”, the SUNA news agency said.

Sudan says Mariam should have used a Sudanese passport, but her lawyer said she does not have one.

Kau Nak, South Sudan's charge d'affaires, said Mariam was entitled to the travel document because her husband and children are South Sudanese.

Wani said on Wednesday that the family “want to get out of here as soon as possible” because of the death threats.

They do not expect to stay long at the embassy, he said on Friday, but the lawyer Mostafa said “there is a criminal case against her... she cannot leave Sudan”. - AFP