Cheating in exams is an age-old problem and one that is becoming an increasing concern for academic institutions around the world. But the two cases revealed in Hong Kong this week are particularly disturbing. They should set alarm bells ringing. The first concerned students on the University of Hong Kong's flagship law course, the Post Graduate Certificate in Laws (PCLL). Sixteen of them were investigated for plagiarism in relation to the same paper. They had apparently copied work from other students and passed it off as their own. After an investigation, four appeared in front of a university disciplinary committee. Two have been expelled. This would be a serious matter for any university, no matter which course was involved. Indeed, it would be worrying even if it took place in a school. But when cheating occurs on a post-graduate course that qualifies students to become lawyers, the concern is much greater. Those involved were on the verge of entering the legal profession, where the highest standards of honesty and integrity are required. They, of all students, should have known better. The case has placed the focus back on the quality of Hong Kong's legal education. As we report today, the Bar Association is also conducting an inquiry - into suspected cheating by two candidates on its Advanced Legal Education programme. This only adds to the concerns. The course is compulsory for barristers-in-waiting, those who have passed the PCLL and are undergoing their professional training. It was introduced in a bid to improve standards. Bar Association chairman Edward Chan King-sang spoke for many when he said it would be very disappointing if candidates were found to have cheated. The two cases have, however, sent out a loud, clear message that plagiarism is wrong and will not be tolerated. Students should take note. Johannes Chan Man-mun, dean of the Law Faculty at the University of Hong Kong, said there had been heated discussions on how to deal with the case involving the PCLL. Whatever these may have involved, there can be no doubting that the expulsion imposed on two of the students is a heavy one. It will jeopardise their chances of being able to pursue a career as a lawyer in Hong Kong. This should act as a deterrent to others. The decision of the disciplinary panel is welcome. But in order to dispel lingering doubts, the university should reveal what action, if any, was taken against the other 14 involved. It has so far only confirmed that two of them were given lighter penalties. The investigation at the Bar Association, meanwhile, is in its early stages. But Mr Chan has rightly made it clear that plagiarism will be taken seriously. If candidates are found to have cheated, they may face disciplinary proceedings. Their prospects of becoming barristers might be adversely affected. Such a stand is necessary in order to uphold the integrity of the profession. But what about plagiarism elsewhere in Hong Kong? The worry is that the two cases this week are only the tip of the ice-berg. Plagiarism is a growing problem around the world, with students able to cut and paste answers from an extensive range of websites. In countries such as the UK and Australia special computer programmes are being used to detect the cheats. Our schools and universities need to step up efforts to ensure all students understand that plagiarism is wrong. And when cases are detected, they must be taken seriously. The need for such action is going to become greater as the schools bring more coursework into the curriculum. The temptation for students to copy will, as a result, increase. In Hong Kong, there is intense pressure on students to achieve good results. Every effort must be made to ensure this is done through their own efforts.