Prosecutors have released Singaporean photographer Leslie Kee, who was arrested Monday in Tokyo on suspicion of selling photo collections containing images of male genitalia, police sources said Thursday.

The prosecutors also released two Japanese organizers of a photo exhibition who allegedly sold photo books containing the images.

The Tokyo District Public Prosecutor's Office skipped seeking detention warrants from a court after the three acknowledged the allegations, the sources said.

Arrested along with Kee, 41, were Hiromi Yoshii, 45, an executive of a company operating a gallery, and Yuko Kanda, 27, an employee of the firm. The prosecutors freed the three Wednesday night, the sources said.

The Metropolitan Police Department said the group sold seven photo books for a total of ¥42,000 to two visitors to the event held Saturday in the Roppongi district of Tokyo.

Japan-based Kee has published works featuring celebrities such as Lady Gaga.

Investigators will continue their investigation into the suspects without detaining them, the sources said.

The sources quoted Kee as saying he attempted to challenge taboos but went too far.

The Penal Code sets penalties of imprisonment of up to two years or a fine of up to ¥2.5 million for those who distribute, sell or display in public obscene material.