TOKYO — The late Emperor Hirohito stopped paying respects to Japan’s war dead at the Yasukuni Shrine in Tokyo because he objected to the enshrinement there of war criminals.

Yesterday’s disclosure, contained in a recently discovered memo, is a devastating blow to nationalists who believe Yasukuni is the only proper place for Japanese to honor countrymen killed in wars since the mid-19th century.

Prime Minister Koizumi is one of many politicians who pay their respects there each year, despite furious objections from China and South Korea that he is honoring war criminals. He will face renewed calls to stop visiting the shrine.

The document, written by one of Hirohito’s closest aides, shows that he shared concerns that the shrine was sullied by the inclusion of the 14 class A war criminals deemed most responsible for leading Japan into World War II.

The men, including a wartime prime minister, Hideki Tojo, were either executed by the Americans after the war or died in prison. They were enrolled at Yasukuni in a secret Shinto ceremony in 1978.

“After that enshrinement I never worshipped there again. That was my conscience,” Hirohito is quoted as saying in the document from 1988, the year before his death.

There is little doubt about the authenticity of the memo, found among the notebooks of the former head of the Imperial Household Agency, Tomohiko Tomita. Tomita, who died in 2002, was a confidant of the emperor.

Hirohito did not visit Yasukuni after 1978 and his son, Emperor Akihito, has never visited since he succeeded.

Until now the reason for this has been a matter of debate, but nationalists must face the fact that their views clash with those of Hirohito, whom they revere.

Hirohito had particularly objected to the enshrinement of a wartime foreign minister, Yosuke Matsuoka, and Toshio Shiratori, the former ambassador to Rome who was instrumental in allying Japan to Nazi Germany and fascist Italy.

Experts say Hirohito rarely criticized individuals, yet the memo quotes him saying: “They even enshrined Matsuoka and Shiratori.”

Mr. Koizumi, who stands down as prime minister in September, said the memo would not affect his views on Yasukuni.

There is speculation that he will fulfill an election pledge to visit the shrine on August 15, the anniversary of the end of World War II.

The date is contentious, as it would imply that he is specifically honoring the dead of Japan’s war of aggression.

Japanese emperors are not simply heads of state but central figures in the Shinto religion. Hirohito’s views will strengthen the argument for the inclusion of the criminals at Yasukuni to be reversed.

“There will be no solution unless class A war criminals are worshipped separately or if another memorial facility, which has no links to a particular religion, is built,” Taku Yamasaki of the ruling Liberal Democratic Party said.