RTHK senior programme officer David Ho Chun-yan revealed to a superior that a woman he had engaged to do freelance work - and who was paid HK$400,000 over six years - was his mother, his lawyer claimed in court yesterday. Lawrence Lok Ying-kam SC put the suggestion to two top officials of RTHK during cross-examination in the case in which Ho is accused of concealing the relationship. But RTHK assistant director Tai Keen-man and head of Chinese broadcasting Philip Chow Wai-choy said they did not know of any such disclosure to Luke Tsang Chee-wah, Ho's immediate supervisor in the 1990s and now head of programme development. Ho, 47, pleaded not guilty in the District Court before Deputy Judge Anthony Yuen Wai-ming yesterday to one charge of misconduct in public office, laid by the Independent Commission Against Corruption. He is alleged to have recruited his mother, Wong Yuk-shan, for freelance work between 1994 and 2000 while he was the producer of the Morning Suite programme. Opening the case, prosecutor Graeme Mackay said Ho's failure to disclose the relationship 'at the very least raised a question of duty and interest'. The court heard that records showed Ms Wong had claimed fees for freelance work including scriptwriting, master of ceremonies, programme assistant and drama artist. Giving evidence for the prosecution, Mr Tai said that in the 1990s, when he was head of Chinese programme services, he had approved 33 claims submitted by Ho to pay Ms Wong's fees. But he said his signature was only a 'procedural requirement' because the content of the form was checked by a principal or senior programme officer before it was submitted for his final approval. He described himself as the 'gatekeeper'. Cross-examined by Mr Lok, he said employees were required to report to their immediate supervisor, verbally or in writing, when there was a conflict of interest and the supervisor had the discretion to decide how to handle the matter. Under civil service regulations in 1992, a breach of the requirement might lead to disciplinary action or dismissal from service, and since 1996 a serious breach would be reported to the ICAC. Mr Tai said it was up to the supervisor to decide the seriousness of the breach. Mr Lok told the court that other members of Ho's family had worked for RTHK, including younger brother Ho Chun-lap who was a programme host, elder sister Ho Chun-wai, who hosted a classical music programme for Radio 4, and Ho Chun-lap's wife, Lau Kwan-cheung, also a programme host. But Mr Tai said he did not know their relationship at that time. Testifying next, Mr Chow said he would not have signed to approve two of the claims had he known Ms Wong was Ho's mother. He said he did not recall who Ho's immediate supervisor was during the mid-1990s. Mr Mackay closed the prosecution case yesterday. The hearing continues on Monday.