Sidney Ng, Samuel Chan and Fong Tsz-ho from the General Union of Hong Kong Speech Therapists were re-arrested and charged on Monday after being granted bail in July.
They appeared at West Kowloon Court to face a charge of conspiracy to print, publish, distribute, display or reproduce seditious publications.
The union’s chairwoman, Lai Man-ling, and vice-chairwoman, Melody Yeung, were charged with the same offence earlier and have been remanded since July 23.
During Monday’s hearing, prosecutors alleged that the books were printed to bring hatred, contempt or disaffection against the government and the administration of justice, to incite people to commit violence and to “counsel disobedience” of the law.
They said they intend to transfer the case to the District Court.
Principal magistrate Peter Law said that although they were not charged under the national security law, the allegations in the case relate to the national security legislation, adding that he had made the relevant considerations before deciding to deny bail to all five defendants.
The case was adjourned to September 24.