The police were investigated for allegedly wiretapping the businessman's phone calls.

wiretapping 是动词 wiretap 的现在分词形式。wiretap 由 wire（电线）和 tap（轻敲、窃听）组成，字面意思是"在电话线上安装窃听装置"，引申为"窃听电话通讯"。 wiretapping 指"电话窃听行为"，通常指未经授权的非法监听活动。