HDFC Bank said investment demand is still strong and credit growth is expected at 18-20% so far.                                            "For the banking system, if GDP (gross domestic product) is growing at 8.5-9%, then the credit growth is seen at about two times the GDP," Aditya Puri, HDFC Bank's managing director, told reporters at press conference.                                            The recent bribes-for-loan scam case will not impact bank's credit growth, Puri added.