Chen initially announced he would leave showbusiness
A computer worker has denied illegally copying and distributing 1,300 photos of Hong Kong film star Edison Chen having sex with famous women.
Sze Ho-chun, 24, pleaded not guilty at Kowloon City Court to copying the pictures from Mr Chen's laptop at the repair shop where he worked.
Photos of Mr Chen with a string of celebrities - which he admits taking - were put on the internet last year.
Chen, 28, has apologised for "all the suffering that has been caused".
The scandal over the photos - which showed Chen with stars including actress Cecilia Cheung, former actress Bobo Chan and pop star Gillian Chung - gripped China, where pornography is officially banned.
Sze Ho-chun denies three charges of obtaining access to a computer with a view to making dishonest gain between 1 and 8 June 2006.
Prosecutors allege that, some time after those dates, he showed some of the images to two female customers before giving a CD with all 1,300 images on to one of them.
The pictures eventually surfaced on the internet in February 2008.
Speaking at that time, Canadian-born actor and hip-hop star Chen told a news conference he was "deeply saddened" and wanted to "apologise to all the people for all the suffering that has been caused".
He said he would be stepping down "indefinitely" from his showbusiness career.
But earlier this week, Mr Chen, who fled to Canada after the pictures emerged, appeared at a Singapore press conference to promote his new film The Sniper.
He appeared despite reported death threats warning him to stay out of the public eye.
According to the AFP news agency, he said: "I'm a little afraid but I have to do what needs to be done so I hope everyone will welcome me and watch my movie."
Mr Chen appeared in the Infernal Affairs trilogy, which was later made into the Hollywood film The Departed.
His other credits include The Grudge 2, with Sarah Michelle Gellar, and The Dark Knight.