The Loss of the Jane Vosper

AN INSPECTOR FRENCH MYSTERY >"Explosions in ships' holds are not uncommon. But it's extremely uncommon not to be able to explain them." The freight liner Jane Vosper is plunged to the bottom of the Atlantic by a series of explosions in her hold. It is clear that something is wrong, as there is no innocent explanation of the cause. The only possibility appears to be that someone has sunk the ship for the insurance money (either for the goods on board or the ship itself). The loss of the goods will cause a problem for The Land and Sea Insurance Co., and they decide to look into matters themselves. When their private detective goes missing, Inspector French of Scotland Yard is called in and he decides that the only way to solve the missing person case is to solve the mystery of the Jane Vosper as well. But even he is baffled, until his hard work and assiduous following of the clues leads him to the correct conclusion. - from Goodreads