Civic Party candidate Paul Zimmerman (pictured) was arrested yesterday after a flare-up with his political opponents while campaigning on the eve of today's Southern District Council by-election. The poll in the Pok Fu Lam constituency is to fill the seat left vacant by the resignation of Ronald Chan Ngok-pang, who quit the council in May to join the Chief Executive's Office as its special assistant. A dispute broke out between Zimmerman, 52, who was with three supporters, and the campaign team for his opponent Ellis Lau Ying-tung, 26, from the Savantas Policy Institute, shortly after 10.30am. As the opponents canvassed at the roundabout at the junction of Sassoon Road and Victoria Road, a row broke out over a campaigning spot. Yeung Hong-kit, a volunteer in Lau's team, was admitted to Queen Mary Hospital after he was allegedly pushed to the ground by Zimmerman. He was later discharged. Lau was away at the time of the incident and his team called the police. Zimmerman and campaign team members from both sides gave statements at Western Police Station. A police spokeswoman said a man suffered a superficial injury to his elbow after allegedly being pushed onto the ground, and that a 52-year-old man was arrested for alleged battery. Zimmerman was released on HK$500 police bail. No charges have been laid. He is required to report to the police station early next month. Last night he said the allegation against him was false. 'It was the best place to say hello to citizens. I was waving at cars there. Then about 10 people from Savantas came pushing for space ... He shuffled in front of our banners and when I touched him on his shoulder, there were all sorts of yelling and screaming, including foul things.' Lau's team later uploaded a video onto YouTube, showing Yeung on the ground and Zimmerman laughing. 'I was laughing because it was all fake. He just lay down. The doctors found no scratches on his body.' Lau said Yeung had bruises on the elbow and scratches on the leg. 'Not only was Mr Yeung injured, when he fell, an easy-mount frame also dropped onto the ground and snapped. You can tell how hard he pushed him. We have left the frame at the police station as evidence.'