Somali militants linked to al-Qaeda have reached a decision on the fate of a French commando who has been held hostage since 2009, according to media reports.

Islamist militants have "reached a unanimous verdict on the fate of Denis Allex," according to a statement posted to Twitter by al-Shabaab's press office,  it also said that the details of the decision will be available in an upcoming message.

The BBC reports Allex is an intelligence agent who was the subject of a failed hostage rescue attempt in the town of Bulo Marer, near Mogadishu, on the weekend.

French special forces went into southern Somalia by helicopter under the cover of darkness on Saturday to try to free Allex, according to Reuters, but the rescue failed after French forces encountered fierce resistance from militants.

There is some confusion over the exact outcome of the mission.

The French government has said it believes Allex was killed during the botched rescue, according to a report from Reuters, but militants claim he is still alive.

Two soldiers died in the failed rescue attempt, including the French military field commander in charge of the operation, according to al-Shabaab's press office.

The operation came hours after French troops intervened in the west African state of Mali, according to the BBC.

The French government has reportedly said the two operations are not linked.