Accounting firm PwC on Monday rejected an anonymous letter that criticised the company's involvement in auditing beleaguered Chinese real estate giant Evergrande, saying the letter contained "false allegations". Heavily indebted Evergrande has become a symbol of the years-long crisis in China's property market and last month its onshore unit was accused of a $78 billion revenue overstatement. Chinese authorities are examining the role of PwC in auditing Evergrande, though no decision regarding penalties has been made, Bloomberg News reported last month. The firm said on Monday it was aware of a letter purportedly written by some PwC partners that was circulating on social media. "We believe the letter contains inaccurate statements and false allegations... (that) could tarnish PwC's…