Prime Minister Junichiro Koizumi received ritual purification when he paid homage to the nation's war dead at Tokyo's Yasukuni Shrine on Monday, an act that critics believe may violate the Constitution, a shrine official said Thursday.
The Constitution prohibits the state from engaging in religious activities.
Critics said the prime minister's actions may fuel the debate over his controversial visit to the Shinto shrine, which honors 14 Class A war criminals in addition to the 2.47 million Japanese soldiers who died in wars through the end of World War II.
According to shrine officials, Koizumi was purified by a priest in the hall of worship after signing his name in the visitors' book.
He also took part in a ritual washing of his hands and mouth.
In a purification ritual, a priest waves a stick featuring strips of mulberry paper over the head of a worshipper while reciting prayers.
Worshippers undergo the ritual to prepare for ceremonies in which they commune with Shinto gods.
After the purification rite, however, Koizumi approached the main sanctuary and bowed only once, avoiding ritual Shinto gestures of bowing twice, clapping twice and bowing once again.
Former Prime Minister Yasuhiro Nakasone, the last prime minister to make an "official" visit to the shrine in 1985, refused to partake in ritual purification because he believed it would violate the Constitution.
It has been reported, however, that priests at the shrine secretly conducted the rite without his knowledge while he was washing his hands and mouth.
The shrine is considered controversial not only because of the war criminals enshrined there, but also because it was the bastion of government-sponsored Shintoism, which was linked to the rise of militarism in Japan before World War II.