Fifty-year-old Ho Wah was a policeman before he left the force and began putting his detective skills to work clearing the mist shrouding some people's lives - by setting up a private investigation bureau. His wife and three children complain he has worked constantly for the past 12 years rather than taking holidays with them. But Mr Ho says he loves the job and likes to go his own way in life. What's on your mind? Life would be much easier if people didn't think in extremes and solved their personal problems in a calm and rational way. My clients range in age from their early 20s to 60 or 70. Some of them burst into tears or think of committing suicide because of their predicaments - even if they're not 100 per cent sure what's actually happening. In many cases, they exaggerate the problems in their minds. Clients approach us when they face a crisis. If we don't handle it properly, their lives could be ruined. People think private investigators are scoundrels or people who've deserted the police force, but we require expert knowledge to carry out genuine investigations and help people. What qualifications are needed for the job? I'm very critical and choosy when hiring hands - detectives must be mature, live normal lives and have no bad habits and no criminal record. Some clients come from complicated backgrounds but we need to follow the law and be firm about our role. What's the most memorable case you've handled? A man approached me in 1991 and asked me to check if his girlfriend was having an affair. But my client was so upset that he sent the guy he thought his girlfriend was seeing a bomb before my investigation finished. The guy was seriously injured and my client is now in jail. What did you learn from the case? Jealousy and misunderstanding can be fatal. In that case, the relationship between the girl and the injured man was not as far developed as my client imagined. He was so stupid. If he had waited until my investigation was completed, tragedy could have been averted. The case further strengthened my belief that we need smart and mature investigators to handle cases when clients are emotionally unstable.