A POLICE constable yesterday insisted he had been punched in the face and kneed in the groin by a decorator after he had searched the man on a street. Constable Ngai Sek-tim was under cross-examination at the trial of six police officers charged with assault. He had earlier described in San Po Kong Court the alleged assault by Wong Kwok-hung, 25, on a Hunghom street on February 17. On trial are Constables Cheung Kin-tak, 24, Tsang Yee-man, 26, Kevin Wong Chi-kin, 23, Lee Ching-cheung, 27, Cheng Wing-keung, 35, and Senior Police Constable Ng Shiu-kwan, 39. Cheung, Lee and Ng have denied charges of common assault while Tsang, Wong and Cheng have pleaded not guilty to assault occasioning actual bodily harm. The alleged victims are Mr Wong and Customs Officers Yeung Hak-kwong, and Tang Kwok-keung, both 28. Constable Ngai yesterday denied a suggestion by prosecutor Michael Lunn that the attack by Mr Wong had not taken place. He also denied having fabricated his claims that Mr Wong had unexpectedly punched him in the face and kneed him in the groin. He further denied he had pretended to have been injured by Mr Wong shortly before police reinforcements arrived. Kevin Egan, counsel for the six defendants, asked Constable Wong if he had seen police assaulting any of the five men who had been arrested that day, which included the three alleged victims. Constable Wong said ''no''. The hearing continues.