Amnesty International said Ms Ibrahim has been shackled in heavy chains since being sentenced to death, a customary practice for prisoners facing execution.
If the verdict had not been overturned, she would have faced a punishment of 100 lashes and execution by hanging.
The release of Ms Ibrahim was an apparent surprise to her husband, with Mr Wani claiming that he found out about it through journalists.
Her lawyer, Mohaned Mostafa said that Ms Ibrahim had been sent "to an unknown house to stay at for her protection and security".
"Her family has been threatened before and we are worried that someone might try to harm her," he told Reuters. Another one of her lawyers, Eman Abdul-Rahim, told The Associated Press that Ms Ibrahim had left prison and was with her husband and two small children.
British Prime Minister David Cameron said he was "absolutely appalled" when he heard about Ms Ibrahim's case, and had urged the Sudanese government to intervene ahead of her reported release today.
And if the reports are accurate, today's court decision comes as the culmination of weeks of campaigning and anger around the world.
Former prime minister Tony Blair called the case a "brutal and sickening distortion of faith".
- UK Independent