A computer technician went on trial Monday accused of stealing the photographs that triggered Hong Kong's notorious celebrity sex scandal.

Sze Ho-chun, 24, allegedly downloaded explicit images from the laptop computer of singer-actor Edison Chen showing him engaging in sex acts with a number of young starlets.

The 1,300 pictures showed stars including singer Gillian Chung and actress Cecilia Cheung naked with Chen in a scandal which tarnished the squeaky clean image of Hong Kong's so-called Canto-pop stars.

The images were shared among millions of internet users in early 2008, forcing the 28-year-old star to issue a public apology, flee Hong Kong and announce his temporary retirement from showbiz.

At the start of a 10-day trial, during which 16 prosecution witnesses are due to testify, Sze Monday pleaded not guilty to three counts of obtaining access to a computer with dishonest intent.

His defence is expected to rest upon the contention that he made no profit from the 1,300 pictures which were stolen from Chen's laptop in 2006 and uploaded onto the internet last year.

Evidence from Edison Chen, which was given in a court in Vancouver when he refused to return to Hong Kong for the trial, was outlined at the start of Monday's hearing at Kowloon City court.

Prosecutors said Chen was a regular customer of Sze at the computer shop where he worked and alleged that Sze passed the photographs to another person who uploaded them onto the internet.

Sze, who faces a potential jail term of up to five years, is said to have downloaded the images while repairing Chen's laptop and burnt them onto a CD before they were uploaded.

Chen, who is currently filming in Singapore, received a warning letter containing a bullet telling him to keep out of the public eye after he made his first public appearance since the scandal earlier this year.