A POLICEWOMAN convicted of three traffic offences had brought disgrace upon the police force, a magistrate said yesterday. Magistrate Polly Lo, fining Ma Wai-kuen $10,000 in Western Court over offences on the night of a fatal traffic accident, said Ma should have reported, rather than participated in, a joy-riding incident. Ma, 25, attached to the Wan Chai Division of the police force, pleaded guilty to traffic summonses of travelling on a police motorcycle without wearing a crash helmet, driving without a licence for a government vehicle, and driving without third party insurance. ''You, being a woman police constable, should be well aware that it was wrong for you to travel on a police motorbike while your colleague was on duty, not to say without wearing a crash helmet,'' Ms Lo said. The magistrate also ordered that Ma's driving licence be suspended for two years. Ma was not represented by legal counsel. The court heard that Constable Charles Lo was patrolling on a motorcycle in Wan Chai when he saw his off-duty colleague Ma in the early hours of May 30 last year. Ma, not wearing a crash helmet, rode as a pillion passenger on Constable Lo's police motorbike from 2 am. She travelled from Lockhart Road to the promenade garden in Convention Avenue. There she met some off-duty colleagues. The group met again at about 3.30 am at the car park of the Hong Kong Academy for Performing Arts. Ma rode the motorbike over a short distance in the car park in the presence of Constable Chan Wai-keung, 23, and two other policewomen. The court heard that Ma, who held a motorcycle licence, did not have a licence for driving a government vehicle. Another off-duty colleague, Cathy Wong Sze-wai, 20, later took over the motorcycle from Ma and rode it in the same car park. Wong lost control of the bike and fell from it. She sustained serious head injuries and died on June 4. The court was told that the accident had been reported to police only after Wong's death aroused suspicions. Last month, Ma and Constable Chan appeared before Magistrate Michael Hill in Eastern Court on two summonses of misleading police by giving false information. They were each accused of misleading police by giving false information at Tang Shiu Kin Hospital at 3.45 am on May 30. Mr Hill transferred the two cases to Western Court for consolidation and adjourned the hearing until yesterday. Yesterday, Ma and Constable Chan appeared separately before Ms Lo. They were told that the two summonses against them had been withdrawn after legal advice had been sought from the Attorney-General's chambers.