Of these, more than half earned HK$5,000 to HK$10,000 a month, while 45 per cent had debts of HK$50,000 to HK$200,000.

The centre's social work supervisor, Joe Tang Yiu-cho, said many gambled to relieve boredom and boost self-esteem. He cited cooks as an example of those who killed time by gambling during short breaks.

'Many feel their lives are boring and aimless,' he said. 'They feel like slaves, having to work such long hours. But when they go to clubs to play mahjong, they are greeted as masters or bosses. Gambling boosts their self-esteem.'

Taxi driver Ah Cheung, 50, said he used to own five taxi licences worth about HK$1 million each in 1989, but lost them all on the casino table. A licence is now worth about HK$3.3 million.

'I used to go to Macau after driving for a few hours in the morning,' he said.

'I didn't find gambling taking up a lot of my money, as I gambled with cash I earned that day. I always thought I could make up for the loss if I worked harder the next day.'

Ah Cheung, who is married with no children, described the 31 years he spent addicted to gambling as a time when he had 'lost his mind'.

'I started gambling when I was 17,' he said. 'There were only two things I cared about - winning more and covering my debts.'

One day in early 2004, when he lost all his money and had to repay a debt of HK$200,000 the next day, he knew he had to quit.

He was so desperate he considered suicide. 'I told my elder brother that I was in a mess and wanted to kill myself. My brother lashed out at me, but he helped me settle the debt and called the gamblers hotline for me,' Ah Cheung said.

After two years of counselling at the centre, Ah Cheung eventually overcame his addiction.

Hoping to help other addicts, he has painted messages promoting the gambling hotline on his taxi.

'Gambling is popular among taxi drivers, but from my experience it is just a waste of time,' he said.