PARIS (Reuters) - Suspicions that a U.S. submarine may have accidentally sunk a French fishing boat, killing five sailors, will be investigated by magistrates, a French appeal court ruled on Friday.

The Bugaled Breizh sank mysteriously in the English Channel on January 15, 2004, a day before NATO forces started military exercises in the area.

A first court ruling had ruled out any military involvement in the incident.

However, the sailors’ families appealed in light of a research report which concluded that the ship may have been pulled under by a U.S. submarine patrolling the area.