ADJ. careful, close, detailed | extensive The authorities conducted an extensive investigation into his tax affairs. | full, thorough | criminal, murder, police | scientific | government
VERB + INVESTIGATION carry out, conduct, pursue Police are still pursuing their investigations. | launch | head, lead | complete
INVESTIGATION + VERB reveal sth, show sth Closer investigation showed this idea to be untenable.
PREP. on ~ On investigation, the noise turned out to be only a door banging. | under ~ The singer is currently under investigation for possessing illegal drugs. | ~ into Police have launched an investigation into the allegations.
PHRASES the subject of an investigation The matter is the subject of a police investigation, and we have been advised not to comment.