Answer: delver

AnswerCrossword Clue
DELVERInvestigator
DELVEROne who probes
delverone that delves (to search in depth)
delverexcavate
delverto search carefully for information
delvermake a careful or detailed search for information delved into the past
delverexamine a subject in detail the book delves into the latest research
delverdig or labor with or as if with a spade