The Chinese actress, who appeared in Crouching Tiger, Hidden Dragon and Memoirs of a Geisha, was accused of sleeping with politician Bo Xilai at least 10 times between 2007 and 2011 in return for monetary gifts, according to a report in the Hong Kong-based tabloid Apple Daily.
Zhang was also accused of having arranged similar deals with a number of other high-profile figures.
Her publicist said in a statement: "We read this outrageous report in the Apple Daily. It sent stone-cold chills down our spines and has left us with a feeling of deep sadness. Why should this devoted and responsible actress have to suffer this kind of slander and defamation?
"Friends have advised us to release a short statement and not take this seriously. The more you argue, the more you will stir up. It would be better to step aside until people lose interest and the lies disappear. The innocent will always be innocent."
Zhang, who has demanded an apology and retraction from the Apple Daily via her lawyers, reportedly posted on her blog that people "can take wind as rain".
Bo was the former mayor of Chongqing, before being driven out of the position amid accusations that he and his wife were involved in the murder of British businessman Neil Heywood.