A MAN was charged yesterday with 15 counts of using his digital camera to film up the skirts of five women in a span of two hours.

Lui Meng Kwong, 30, allegedly committed the 'upskirt' offences on July 8 at the Singapore Expo Hall 5 in Changi.

Lui is out on $10,000 bail, and will appear in court again on Wednesday.

His court appearance came as police told The Straits Times that in recent years, there has been an increase in such outrage of modesty offences using electronic gadgets - a digital-age version of voyeurism by peeping Toms.

Their statistics show a yearly spike: Last year, there were 50 cases of such gadget-equipped voyeurs, who use mostly small, easily concealed camera phones - some as small as a man's palm.

This is nearly double the 28 cases in 2004. In 2005, there were 39 cases.

Clearly, compact and even remotely operated camera phones and digital cameras have emboldened voyeurs to openly commit their acts in busy areas, with staircases and moving escalators the favoured 'shooting' locations.

The culprits tend to snap 'upskirt' pictures, though others are also using modern technology and ever-smaller video cameras to peep into showers.

Perpetrators caught here have included hawkers, teachers and professionals like engineers and a doctor.

Police spokesman Toh Boon Ngee said the culprits tended to be local men. Several were teenagers.

Because the cameras are easily concealed in, say, shopping bags or briefcases, many other 'upskirt' voyeurs may have got away scot-free.

One who was caught in the act and arrested as a result was 38-year-old Daniel Bay.

The maintenance officer, married with a young daughter, was caught recording an 'upskirt' clip of a 29-year-old accounts manager at Novena Square in May, while they were on an escalator.

Bay, who was put behind bars for two months last month, had 13 similar charges taken into consideration.

Apart from the typical 'upskirt' approach, some voyeurs have tried other variations.

Last September, Michel Tan attached a pinhole spy camera to the side of his backpack.

The 28-year-old connected this to a digital video camera inside the bag, which he put on the floor of an MRT train beneath a 20-year-old woman's skirt.

She was engrossed in her book, but someone told her something was amiss. The married man was arrested and jailed for a month.

Psychiatrists think a main motivation for these digital-age voyeurs is the sexual thrill they get from the act.

Easy access to pornographic material, especially video clips from a multitude of Internet websites, may play a part too.

The experts explained that after a time, second-hand thrills from viewing pornographic images off the Internet may wear off - leading to the next step: their own 'upskirt' photos.

A Mount Elizabeth Medical Centre consultant psychiatrist, Dr Brian Yeo, has treated recovering 'upskirt' voyeurs.

He said: 'Sometimes when the men do it, they are in a state of stimulation by what they've viewed online the night before.

'They usually regret their actions after the incident.'

Police advise women to be alert on staircases and escalators, especially when someone seems too close.

'If you suspect someone is trying to take compromising pictures of you, remain calm,' said Assistant Superintendent Toh, adding victims should then move to open premises or crowded places and call the police for help.

ADDITIONAL REPORTING BY ELENA CHONG