The ongoing protests in Hong Kong have made investigations into corruption more complex despite a 14 per cent drop in the number of complaints lodged, according to the city’s graft-buster.But the agency refused to reveal details of its probe into accusations against police of failing to protect the public in the Yuen Long mob attacks last July, only pledging to look at the case thoroughly.The remarks by the Independent Commission Against Corruption (ICAC) were made on Tuesday at an annual graft…