diàochá qǔzhèng
“调查” v. inquire/look into; investigate; survey(Source: 《新世纪汉英大词典》)
“取证” v. collect/gather evidence(Source: 《新世纪汉英大词典》)
“调查取证” v. conduct investigation and obtain evidence(Source: 《新世纪汉英大词典》)
新闻例句
调查组的人士表示,待调查取证工作结束后,他们将对相关责任人进行责任追究,并及时向社会公布处理结果。(Source: 新华网)
Officials said they will hold those in charge accountable and promptly release the results after concluding their investigation.