The appeal court in French Polynesia is to announce its ruling on October the 27th in a case brought by a former spy of the GIP intervention force.
The former spy, Vetea Guilloux, was jailed for malicious slander last October after alleging that a journalist, Jean-Pascal Couraud, was kidnapped and drowned by fellow GIP members off Tahiti in 1997.
Mr Guilloux was released weeks later pending his appeal.
The court has now been told that the circumstances surrounding the journalist's disappearance are not clear enough to decide that Mr Guilloux's account amounts to a lie.
The case came nine months after the journalist's family lodged a murder complaint against unknown persons.
Mr Guilloux had been working as a spy for the GIP's intelligence unit but has given differing accounts of what happened to Jean-Pascal Couraud.
At the latest hearing, a 30-strong GIP was present, including its former head, Rere Puputauki, who has led three anti-government rebellions this year.