A total of 75 prisoners have graduated from the Correctional Services Department's Ethics College, receiving diplomas in education.

Among the graduates was Tong Ying-kit, the first person charged under the National Security Law.

Speaking at the graduation ceremony on Thursday, Tong reflected on his past, saying that he had been influenced by radical comments, misinformation and the social atmosphere at the time.

He said he was grateful for the education opportunities given to him, and expressed his desire to make positive contributions to society.

Secretary for Security Chris Tang, who attended the ceremony, congratulated the graduates and said he was proud of their achievements.

He emphasised the role of the college in guiding them towards a more constructive path in life and instilling in them the importance of upholding ethical values.

Speaking to reporters after the event, Tang praised the achievements of Olympic gold medallist Vivian Kong and expressed regret that some people targeted and criticised her.

"Kong is supportive of the government and she condemns violence. I think the stance should be encouraged, and everyone should embrace that," he said.

Kong won gold in the individual epee event at the Paris Olympic Games and is joining the Hong Kong Jockey Club as an assistant external affairs manager.