A Cairo court acquitted Aya Hijazi, a dual US-Egyptian citizen and seven other people who worked with street children on Sunday, Al Jazeera reported.
Hijazi is a lawyer and charity worker who along with her husband Mohamed Hassanein founded an NGO called Belady in 2013, to help Egypt's street children.
Egyptian authorities arrested Hijazi, Hassanein and others who worked for the NGO in May 2014 on charges that include engaging in human trafficking, kidnapping, sexual exploitation and torture.
All detainees in the case had maintained their innocence. Their detention was condemned by various human rights organizations, including Human rights watch.
Joe Stork, deputy Middle East director for Human Rights Watch even called the case "a travesty of justice."
According to Al Jazeera, "the trial was delayed multiple times on what human rights groups said were absurd pretexts, such as the inability to turn on a computer at a court hearing."
Many also criticized the fact that the defendants had been detained for 33 months, in violation of Egyptian law which states that the maximum period for pre-trial detention is 24 months.
After news of the acquittal came out, Stork commented, saying that even though the defendants are now free, the system that subjected them to injustice "for nearly three years remains unchanged."
The prosecution still holds the right to appeal the most recent verdict in a case that has come to be seen as part of a wider crackdown on civil society under President Abdel Fatah El Sisi's rule.
Given the fact that Hijazi holds a U.S. passport, many called on her high-profile case to be discussed during al-Sisi's recent visit to the U.S.
In a phone interview with the New York Times, Hijazi's brother said that senior American officials eventually told the family that her case had been raised during al-Sisi's visit to President Trump.
Her acquittal comes two weeks after the two leaders met.
"The dream doesn't die. On the contrary, the dream becomes stronger."
Upon their release from prison both Hijazi and her husband vowed to continue their charity work.
"We were delayed for three years ... starting today, God willing, there won't be any children without shelter," Hassanein told reporters.
Dressed in a white prison uniform, Hijazi also spoke to reporters. Commenting on the acquittal she said, "humanity became free, and the dream doesn't die. On the contrary, the dream becomes stronger."