The sudden death of the news media tycoon Robert Maxwell by drowning almost 15 years ago was as dramatic and mysterious as his life. Those who believe that it was not an accident — that perhaps he jumped, rather than fell, from his yacht into the Atlantic in November 1991 — have generally based their theory on the troubles overwhelming his vast business empire, which collapsed soon after he died.

But business was not the only thing potentially troubling Mr. Maxwell in the last days of his life, according to an account in the newspaper The Independent on Friday. The paper said that Mr. Maxwell, who owned the Mirror Group of newspapers, was also being investigated as a possible war criminal in connection with an episode in which, as a captain in the British Army during World War II, he shot and killed an unarmed German civilian.