Police have arrested four directors of a charity that helps students quit drugs, on suspicion of conspiracy to defraud.

Officers on Thursday said the four men, aged between 34 and 77, are directors of the Christian Zheng Sheng Association, which runs a college with the same name.

Three other directors who are not in Hong Kong are being put on the force's wanted list, including the college head Alman Chan.

Police said that in 2020, Chan made appeals on social media and in the press for donations for the college, saying it had financial difficulties.

"According to our investigation, the association received some HK$45 million in donations in 2020, but the college ended up getting less than 10 percent of the donations," police chief inspector Abraham Yu alleged.

Officers said government departments have been asked to help ensure the smooth running of the college, which has 17 students.