TOKYO (AFP) - A conservative Japanese daily on Saturday apologised for carrying an advertisement for books by an author who claims Jewish people were behind the country's 2011 earthquake-tsunami disaster.

The advert ran in a Nov 26 regional edition of the Sankei Shimbun national newspaper, and promoted the works of Richard Koshimizu, a self-styled journalist and activist who also blames Jews for the Sept 11, 2001 terror attacks in the United States.

Koshimizu has claimed the Holocaust was a "fabrication" designed to establish the state of Israel.

"It is extremely regrettable that an advertisement of this content was carried and delivered to our readers, and we deeply apologise to readers and the people of the Jewish community," Sankei president Takamitsu Kumasaka said in a statement published in the paper.

"It was obvious there was a fault in our screening of advertisements," he said.

Kumasaka added he had received a letter of protest from Abraham Cooper, associate dean of Jewish rights group the Simon Wiesenthal Center over the advert.

"The Sankei considers the Holocaust by the Nazis as an unforgivable, heinous crime and does not side," the president said.

The Sankei said the ad was in the Tokai/Hokuriku edition covering central Japan, which has a circulation of 5,000 copies.