noun
corroborative investigation; search for supporting evidence
Used in legal, police, or journalistic contexts for an investigation aimed at finding evidence that backs up a claim or suspicion.
警察は容疑者の供述を確認するため、裏付け捜査を進めている。
The police are conducting a corroborative investigation to verify the suspect's statement.
Compound of 裏付け (うらづけ, 'backing, supporting evidence') and 捜査 (そうさ, 'investigation').