Two police officers caught on tape fabricating evidence against people accused of running a sex den were found guilty yesterday of perverting the course of justice. Yeung Ka-ho, 33, and Chow Chi-pang, 35, were also convicted in the District Court of misconduct in public office. Their conversations were taped by a former policewoman whose husband was a defendant in the 2007 trial. Sentencing was adjourned to May 12 for background reports.