A special rapporteur for the United Nations has effectively retracted her earlier allegation that 13 percent of schoolgirls in Japan are engaged in enjo kosai, or compensated dating, the government's top spokesman said Wednesday in Tokyo.

Chief Cabinet Secretary Yoshihide Suga said Maud de Boer-Buquicchio, special rapporteur on the sale of children, child prostitution and child pornography, had sent a letter in which she backed away from her earlier claim. De Boer-Buquicchio visited Japan late last month.

The government had strongly protested to the Office of the High Commissioner for Human Rights regarding comments by de Boer-Buquicchio, demanding that she explain on what data her claim was based.

In the letter, she admitted there is "no public, recent" data to back up her allegation, and promised not to use the figure in a report she plans to submit to the United Nations, Suga told a regular news conference.

"We take this explanation as an effective retraction" of her remark, Suga said.

On Tuesday, Suga told reporters that Japan "could never accept" her claim because its basis was unclear and it could "help cause international misunderstandings" about schoolgirls in Japan.

Enjo kosai, which often involves prostitution, was once considered rampant among certain schoolgirls, in particular in the late 1990s.

A 1996 survey by the Tokyo Metropolitan Government found that 4.6 percent of 504 female high school students in Tokyo who responded said they had engaged in enjo kosai at least once.

A 1997 survey by the Benesse group, an Okayama-based education company, likewise found that 4.4 percent of 868 high school girls in Tokyo and Saitama Prefecture who responded said they had engaged in enjo kosai.