The Sudanese government has summoned both the United States and South Sudan ambassadors following the re-arrest of Christian convert Miriam Ibrahim over "forged" travel documents.
Sudan's National Intelligence and Security Services agency said that Ibrahim had attempted to travel to the US using an American visa and documents issued by South Sudan.
A post on Facebook, in which the agency referred to her using her Muslim name, read: "The airport passport police arrested Abrar after she presented emergency travel documents issued by the South Sudanese embassy and carrying an American visa."
"The Sudanese authorities considered (the action) a criminal violation, and the Foreign Ministry summoned the American and South Sudanese ambassadors," it added.
Mariam Yahya Ibrahim, who was re-arrested today hours after her release from the death row, has been sent to a police station in Khartoum for questioning over providing forged information, her lawyer said.
The 27-year-old Sudanese Christian convert was detained along with her American husband and two children as they tried to board a flight at Khartoum airport earlier today.
It was unclear where they were heading, but two diplomats said they suspected they were trying to go to the United States via either Cairo or Juba.
Her lawyer, Mohaned Mostafa, told the Reuters news agency he was with her at the police station and the police wanted to question her about providing forged information.
He was unable to immediately provide further details.
Sudanese authorities have re-arrested Meriam Ibrahim just one day after she was freed from death row. She is being detained along with her husband and two children after the family tried to board a plane in Khartoum.
A Sudanese Christian woman who was sentenced to death for converting from Islam has been pictured smiling alongside her husband and children after her release by the country's authorities.
Following their release, 27-year-old Meriam Ibrahim, her 19-month-old son Martin and four-week old daughter, Maya - who was delivered in prison - are now living in an undisclosed location until they can leave the country safely", campaign group Hardwired Global said in a statement today.