A U.S. citizen sentenced last year to 22 years in a Nicaraguan prison for alleged drug trafficking has been freed.

Jason Puracal, whose case became a rallying point for human rights activists, flew out of Managua Friday, a day after he and his co-defendants left the prison. Puracal has not spoken to reporters. His destination is unknown.

An appeals panel threw out the charges against Puracal and the others. It ruled that the sentencing judge did not allow the defense to submit evidence.

Puracal was working for a real estate agency when he was arrested in 2010. Prosecutors say the company bought properties with drug money.

Puracal insisted he was innocent and human rights groups took up his cause. They include a lawyer who had previously represented Burmese opposition leader Aung San Suu Kyi and South African activist Desmond Tutu.