"We have freed the Chinese ship. We have received ... the agreed ransom this morning and the ship has already sailed away," a pirate who identified himself as Hussein told Reuters by telephone from the pirate haven of El-Dhanane.
Andrew Mwangura, a Kenya-based former maritime official and now maritime editor of the Somalia Report confirmed the release but said he did not know whether a ransom had been paid.
Armed pirate gangs plaguing the strategic waters off Somalia that link Europe and Asia typically demand multi-million dollar ransoms for a vessel's release.
A report by the U.S.-based One Earth foundation published earlier this month said pirates' hostages were increasingly the victims of beatings, confinement and in some cases torture.