A senior Egyptian prison official and the country's official news agency say Al-Jazeera's Australian reporter Peter Greste has been freed from prison and is on his way to Cairo airport to leave the country.

The agency said his release on Sunday, after more than a year behind bars, followed a presidential "approval" and both said it was coordinated with the Australian Embassy in Cairo.

The official spoke on condition of anonymity because he was not authorized to speak to the media.

Greste, Egyptian-Canadian Mohammed Fahmy, and Egyptian Mohammed Baher were sentenced to at least seven years in prison on terrorism-related charges last year in a trial that was described as a sham by rights groups.